Fix grammatical issues in README

COLLABORATOR_GUIDE.md

@@ -4,7 +4,7 @@ As a collaborator, you will be involved with axios with some administrative resp
 
 1. __Adhere to and help enforce the Code of Conduct.__ It is expected that you have read the [code of conduct](https://github.com/axios/axios/blob/master/CODE_OF_CONDUCT.md) and that you agree to live by it. This community should be friendly and welcoming.
 
-1. __Triage issues.__ As a collaborator, you may help sort through the issues that are reported. Issues vary from bugs, regressions, feature requests, questions, etc. Apply the appropriate label(s) and respond as needed. If it is a legitimate request, please address it, otherwise feel free to close the issue and include a comment with a suggestion on where to find support. If an issue has been inactive for more than a week (i.e., the owner of the issue hasn’t responded to you), close the issue with a note indicating stales issues are closed; it can always be reopened if needed. In the case of issues that require a code change, encourage the owner to submit a PR. For less complex code changes, add a very simple and detailed checklist, apply the “first-timers-only” label, and encourage a newcomer to open source to get involved.
+1. __Triage issues.__ As a collaborator, you may help sort through the issues that are reported. Issues vary from bugs, regressions, feature requests, questions, etc. Apply the appropriate label(s) and respond as needed. If it is a legitimate request, please address it, otherwise feel free to close the issue and include a comment with a suggestion on where to find support. If an issue has been inactive for more than a week (i.e., the owner of the issue hasn’t responded to you), close the issue with a note indicating stale issues are closed; it can always be reopened if needed. In the case of issues that require a code change, encourage the owner to submit a PR. For less complex code changes, add a very simple and detailed checklist, apply the “first-timers-only” label, and encourage a newcomer to open source to get involved.
 
 1. __Answer questions.__ It is not expected that you provide answers to questions that aren’t relevant, nor do you need to mentor people on how to use JavaScript, etc. If the question is not directly about the module, please close the issue. If the question stems from poor documentation, please update the docs and consider adding a code example. In any event try to be helpful and remember that there’s no such thing as a stupid question.
 

README.md

@@ -529,7 +529,7 @@ The response for a request contains the following information.
   statusText: 'OK',
 
   // `headers` the HTTP headers that the server responded with
-  // All header names are lower cased and can be accessed using the bracket notation.
+  // All header names are lowercase and can be accessed using the bracket notation.
   // Example: `response.headers['content-type']`
   headers: {},
 
@@ -801,7 +801,7 @@ cancel();
 ```
 
 > Note: you can cancel several requests with the same cancel token/abort controller.
-> If a cancellation token is already cancelled at the moment of starting an Axios request, then the request is cancelled immediately, without any attempts to make real request.
+> If a cancellation token is already cancelled at the moment of starting an Axios request, then the request is cancelled immediately, without any attempts to make a real request.
 
 > During the transition period, you can use both cancellation APIs, even for the same request:
 
@@ -962,7 +962,7 @@ try {
 
 ## Online one-click setup
 
-You can use Gitpod an online IDE(which is free for Open Source) for contributing or running the examples online.
+You can use Gitpod, an online IDE(which is free for Open Source) for contributing or running the examples online.
 
 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/axios/axios/blob/master/examples/server.js)