fix(docs): change bash to shell in code language blocks

docs/blog/2017-02-21-1-0-progress-update-where-came-from-where-going/index.md

@@ -229,7 +229,7 @@ the base theme to meet their specific requirements.
 Themes (like plugins) will be published on NPM. So soon, starting a new Gatsby
 blog will be as simple as:
 
-```bash
+```shell
 npm install --save gatsby-super-cool-theme
 gatsby build --theme gatsby-super-cool-theme
 ```

docs/blog/2017-07-19-creating-a-blog-with-gatsby/index.md

@@ -80,7 +80,7 @@ blog, you can use the following plugins:
 
 with the following command:
 
-```bash
+```shell
 yarn add gatsby-plugin-catch-links gatsby-plugin-react-helmet
 ```
 
@@ -122,7 +122,7 @@ Markdown, let's add that [`gatsby-source-filesystem`][gatsby-source-filesystem]
 plugin. Similarly to the previous step, install the plugin and then inject
 into your `gatsby-config.js`, like so:
 
-```bash
+```shell
 yarn add gatsby-source-filesystem
 ```
 
@@ -173,7 +173,7 @@ installed.
 
 The process should be familiar by now, install and then add to config.
 
-```bash
+```shell
 yarn add gatsby-transformer-remark
 ```
 

docs/blog/2017-10-01-migrating-my-blog-from-hexo-to-gatsby/index.md

@@ -110,7 +110,7 @@ should have a file structure that looks something like this:
 
 Now run the Gatsby dev server to make sure everything works:
 
-```bash
+```shell
 npm run develop
 ```
 
@@ -180,7 +180,7 @@ If you play around with GraphiQL you'll notice there's not that much there.
 Let's fix that. We need to teach Gatsby how to query the file system. Luckily
 this is so common it's been done for you. Install the file system source plugin:
 
-```bash
+```shell
 npm i --save gatsby-source-filesystem
 ```
 
@@ -229,7 +229,7 @@ Being able to query files is a big win, and if you have a directory of HTML
 files this is all you will need. But if you want to render markdown files as
 HTML you will need another plugin. Let's add that now:
 
-```bash
+```shell
 npm i --save gatsby-transformer-remark
 ```
 

docs/blog/2018-04-04-gatsby-contentful-starter-tutorial/index.md

@@ -32,19 +32,19 @@ This guide assumes that you have [GatsbyJS installed](/docs/) and, optionally, a
 
 Start by using this with the Gatsby CLI:
 
-```bash
+```shell
 gatsby new contentful-starter https://github.com/contentful-userland/gatsby-contentful-starter
 ```
 
 Alternatively, you can also clone a sample repo from GitHub:
 
-```bash
+```shell
 git clone git@github.com:contentful-userland/gatsby-contentful-starter.git
 ```
 
 And go into the directory and install the required dependencies with:
 
-```bash
+```shell
 npm install
 ```
 

docs/blog/2018-06-07-build-a-gatsby-blog-using-the-cosmic-js-source-plugin/index.md

@@ -32,25 +32,25 @@ In order to start working on the blog, we first have to set up the environment.
 
 First, install the Gatsby CLI:
 
-```bash
+```shell
 npm install --global gatsby-cli
 ```
 
 Create a new site based on the Gatsby Cosmic JS starter:
 
-```bash
+```shell
 gatsby new gatsby-blog-cosmicjs
 ```
 
 Enter in your project's folder:
 
-```bash
+```shell
 cd gatsby-blog-cosmicjs
 ```
 
 Start the server:
 
-```bash
+```shell
 npm run develop
 ```
 
@@ -68,13 +68,13 @@ In our case, we are using [Cosmic JS](https://cosmicjs.com). We need a source pl
 
 Install the source plugin with the following command:
 
-```bash
+```shell
 npm install --save gatsby-source-cosmicjs
 ```
 
 We're going to use a couple other plugins later, so let's install them here:
 
-```bash
+```shell
 npm install --save gatsby-plugin-offline gatsby-source-filesystem
 ```
 

docs/blog/2018-1-18-strapi-and-gatsby/index.md

@@ -99,7 +99,7 @@ _Requirements: please make sure [Node 10](https://nodejs.org/en/download/) (or h
 
 Install Strapi using npm:
 
-```bash
+```shell
 npm i strapi@alpha -g
 ```
 
@@ -109,13 +109,13 @@ _Note: Strapi v3 is still an alpha version, but it will be fine for this tutoria
 
 Create a directory named `tutorial`:
 
-```bash
+```shell
 mkdir tutorial
 ```
 
 Navigate into `tutorial`and then, using a single command, set-up and start your project inside your `tutorial` folder:
 
-```bash
+```shell
 cd tutorial
 strapi new cms --quickstart
 ```
@@ -138,13 +138,13 @@ After installation, and initial use, you will often close your project and work
 
 Enter inside your project folder, on the command line, (in this case `tutorial/`, :
 
-```bash
+```shell
 cd cms
 ```
 
 From `cms/`, launch the Strapi server:
 
-```bash
+```shell
 strapi start
 ```
 
@@ -215,29 +215,29 @@ _Important links from Video:_
 
 First, install Gatsby CLI:
 
-```bash
+```shell
 npm install --global gatsby-cli
 ```
 
 #### Generate a Gatsby project
 
 In the folder `tutorial` that you previously created, generate your brand new blog:
 
-```bash
+```shell
 gatsby new blog
 ```
 
 #### Start in development mode
 
 Enter in your project's folder:
 
-```bash
+```shell
 cd blog
 ```
 
 Start the server:
 
-```bash
+```shell
 gatsby develop
 ```
 
@@ -255,7 +255,7 @@ In this example, we are using Strapi. Obviously, we are going to need a source p
 
 Let's install it:
 
-```bash
+```shell
 npm install --save gatsby-source-strapi
 ```
 

docs/blog/2018-11-05-deploying-gatsby-to-azure/index.md

@@ -21,7 +21,7 @@ To complete this tutorial you will need the following tools:
 
 Install Node from the [Node website](https://nodejs.org/en/) and check it's installed by checking the version from your terminal.
 
-```bash
+```shell
 node -v
 v10.9.0
 ```
@@ -30,7 +30,7 @@ Install VS Code from the [VS Code website](https://code.visualstudio.com/).
 
 Next, we can install the important part! [Gatsby](https://gatsbyjs.org/) from your terminal, run:
 
-```bash
+```shell
 npm install --global gatsby-cli
 + gatsby-cli@2.4.2
 updated 1 package in 4.868s
@@ -44,7 +44,7 @@ Next you will create the blog from the handy [Gatsby Starter Blog](https://githu
 
 From your terminal run
 
-```bash
+```shell
 gatsby new azure-blog https://github.com/gatsbyjs/gatsby-starter-blog
 
 info Creating new site from git: https://github.com/gatsbyjs/gatsby-starter-blog.git
@@ -61,7 +61,7 @@ info Installing packages...
 
 You can now view your website by running
 
-```bash
+```shell
 cd azure-blog
 npm run develop
 ```
@@ -113,7 +113,7 @@ Change the option to `enabled`, set a default document name of `index.html` and
 
 You are now ready to produce a production build of your blog. Make sure you're in the blog folder and then run.
 
-```bash
+```shell
 gatsby build
 
 success open and validate gatsby-config — 0.010 s

docs/blog/2019-11-21-how-to-convert-an-existing-gatsby-blog-to-use-mdx/index.md

@@ -21,15 +21,15 @@ It can be a big tricky to add MDX to an existing blog. The following 5 steps wil
 
 You can also see the [full changes in PR #19580](https://github.com/gatsbyjs/gatsby/pull/19580/files) for an overview of the changes you have to make to get MDX working. As stated above, this introduces changes to [Gatsby's blog starter](https://github.com/gatsbyjs/gatsby-starter-blog/tree/master), which you can install with Gatsby CLI.
 
-```bash
+```shell
 gatsby new my-blog-starter https://github.com/gatsbyjs/gatsby-starter-blog
 ```
 
 ### Step 1
 
 Install [gatsby-plugin-mdx](/packages/gatsby-plugin-mdx/), the official plugin for using MDX with Gatsby. Also install `gatsby-plugin-feed-mdx` for our RSS feeds. Finally, install `@mdx-js/mdx` and `@mdx-js/react`.
 
-```bash
+```shell
 npm install --save gatsby-plugin-mdx gatsby-plugin-feed-mdx @mdx-js/mdx @mdx-js/react
 ```
 
@@ -102,7 +102,7 @@ Then, replace `gatsby-plugin-feed` with `gatsby-plugin-feed-mdx`. This will allo
 
 Now, since we're no longer using `gatsby-transformer-remark` and `gatsby-plugin-feed`, you can uninstall them.
 
-```bash
+```shell
 npm uninstall --save gatsby-transformer-remark gatsby-plugin-feed
 ```
 

docs/blog/2019-12-20-integrate-tinacms-with-your-gatsby-website/index.md

@@ -24,7 +24,7 @@ Want to see a more advanced example of TinaCMS integrated with a Gatsby website?
 
 First we need to get a local development environment set up for the site. Please reference the Gatsby Starter Blog [README](https://github.com/gatsbyjs/gatsby-starter-blog/#readme) for extra notes on this.
 
-```bash
+```shell
 gatsby new tina-tutorial https://github.com/gatsbyjs/gatsby-starter-blog
 cd tina-tutorial
 ```
@@ -33,7 +33,7 @@ cd tina-tutorial
 
 As usual when setting up a new tool, we need to install a few packages. We will install `gatsby-plugin-tinacms`, which sets up the core Tina functionality. Along with that, we'll need the peer-dependency, `styled-components`, to keep the sidebar pretty. Since this site uses markdown, we'll install `gatsby-tinacms-remark`. And `gatsby-tinacms-git` will setup our Git API.
 
-```bash
+```shell
 yarn add gatsby-plugin-tinacms gatsby-tinacms-remark gatsby-tinacms-git styled-components
 ```
 

docs/blog/2020-01-08-git-workflows/index.md

@@ -84,7 +84,7 @@ Our `pt1` PR is approved (🎉), but now we have to reconcile our `pt2` branch.
 
 We check out the `pt2` branch and rebase it onto the updated `pt1` branch:
 
-```bash
+```shell
 $ git checkout feat/headless-cms-pt2
 $ git rebase feat/headless-cms-pt1
 ```
@@ -103,7 +103,7 @@ In this alternative flow, we're _leveraging_ Git to show us what work needs to b
 
 Once we've fixed all the conflicts, we can finish up our rebase by running the following:
 
-```bash
+```shell
 # stage all the changes we just made
 $ git add .
 
@@ -127,7 +127,7 @@ You'll notice that our `C` commit—the only commit in our `pt2` branch—has be
 
 Because we've rewritten the history, by turning `C` into `E`, we need to force-push to update our PR on GitHub:
 
-```bash
+```shell
 $ git push origin feat/headless-cms-pt2 -f
 ```
 
@@ -226,7 +226,7 @@ The Git history pollution isn't a huge deal, since we'll have the chance to squa
 
 If you do wind up squash-merging a branch, you'll need to manually snip out the duplicate commits. You can do this with an [interactive rebase](https://hackernoon.com/beginners-guide-to-interactive-rebasing-346a3f9c3a6d):
 
-```bash
+```shell
 $ git checkout feat/headless-cms-pt2
 $ git rebase -i feat/headless-cms
 # A popup will open, presenting you with a list of commits.
@@ -240,7 +240,7 @@ The work we're doing in this example to migrate to a headless CMS might take a w
 
 To accomplish this, we'll do some more local rebasing:
 
-```bash
+```shell
 # Update our local state
 $ git checkout master
 $ git pull origin master

docs/blog/gatsbygram-case-study/index.md

@@ -530,7 +530,7 @@ It's easy to create your own "Gatsbygram" site from an Instagram account.
 
 ### Instructions on setting up your own Gatsbygram site.
 
-```bash
+```shell
 # Clone the Gatsby repo.
 git clone -b 1.0 git@github.com:gatsbyjs/gatsby.git
 cd gatsby/examples/gatsbygram

docs/docs/ab-testing-with-google-analytics-and-netlify.md

@@ -25,7 +25,7 @@ The following example changes the color of the header for a site using [Gatsby's
 
 Once you're finished with your first variation, commit your changes to `master`, [create a new remote repository on GitHub](https://help.github.com/en/github/getting-started-with-github/create-a-repo) if you don't have one already, and push your changes.
 
-```bash
+```shell
 git add src/components/header.js
 git commit -m "Change header background color"
 git remote add origin [your remote repo URL]
@@ -34,7 +34,7 @@ git push -u origin master
 
 To create your second variation, create a new branch.
 
-```bash
+```shell
 git checkout -b heading-variation
 ```
 

docs/docs/end-to-end-testing.md

@@ -68,7 +68,7 @@ A good use case for writing automated end-to-end tests is asserting **accessibil
 
 To use cypress-axe, you have to install the `cypress-axe` and [axe-core](https://github.com/dequelabs/axe-core) packages. You'll also use some commands from [@testing-library/cypress](https://testing-library.com/docs/cypress-testing-library/intro) to select elements — see [best practices for selecting elements](https://docs.cypress.io/guides/references/best-practices.html#Selecting-Elements).
 
-```bash
+```shell
 npm install --save-dev cypress-axe axe-core @testing-library/cypress
 ```
 

docs/docs/gatsby-image.md

@@ -14,7 +14,7 @@ To start working with Gatsby Image, install the `gatsby-image` package along wit
 
 A common way to source images is to install and use `gatsby-source-filesystem` to connect your local files, but other source plugins can be used as well, such as `gatsby-source-contentful`, `gatsby-source-datocms` and `gatsby-source-sanity`.
 
-```bash
+```shell
 npm install --save gatsby-image gatsby-plugin-sharp gatsby-transformer-sharp
 ```