docs: Fix some grammar issues (#15837)

* Change 'an `.eslintrc.js`' to 'a `.eslintrc.js`'

docs/src/user-guide/configuring/configuration-files.md

@@ -156,7 +156,7 @@ your-project
   └── test.js
 ```
 
-If there is an `.eslintrc` and a `package.json` file found in the same directory, `.eslintrc` will take priority and `package.json` file will not be used.
+If there is a `.eslintrc` and a `package.json` file found in the same directory, `.eslintrc` will take priority and `package.json` file will not be used.
 
 By default, ESLint will look for configuration files in all parent folders up to the root directory. This can be useful if you want all of your projects to follow a certain convention, but can sometimes lead to unexpected results. To limit ESLint to a specific project, place `"root": true` inside the `.eslintrc.*` file or `eslintConfig` field of the `package.json` file or in the `.eslintrc.*` file at your project's root level. ESLint will stop looking in parent folders once it finds a configuration with `"root": true`.
 

docs/src/user-guide/configuring/index.md

@@ -13,7 +13,7 @@ eleventyNavigation:
 ESLint is designed to be flexible and configurable for your use case. You can turn off every rule and run only with basic syntax validation or mix and match the bundled rules and your custom rules to fit the needs of your project. There are two primary ways to configure ESLint:
 
 1. **Configuration Comments** - use JavaScript comments to embed configuration information directly into a file.
-1. **Configuration Files** - use a JavaScript, JSON, or YAML file to specify configuration information for an entire directory and all of its subdirectories. This can be in the form of an [`.eslintrc.*`](./configuration-files#configuration-file-formats) file or an `eslintConfig` field in a [`package.json`](https://docs.npmjs.com/files/package.json) file, both of which ESLint will look for and read automatically, or you can specify a configuration file on the [command line](https://eslint.org/docs/user-guide/command-line-interface).
+1. **Configuration Files** - use a JavaScript, JSON, or YAML file to specify configuration information for an entire directory and all of its subdirectories. This can be in the form of a [`.eslintrc.*`](./configuration-files#configuration-file-formats) file or an `eslintConfig` field in a [`package.json`](https://docs.npmjs.com/files/package.json) file, both of which ESLint will look for and read automatically, or you can specify a configuration file on the [command line](https://eslint.org/docs/user-guide/command-line-interface).
 
 Here are some of the options that you can configure in ESLint: