Fix documentation in the Readme file & Contributing file

Author: toofff

CONTRIBUTING.md

@@ -49,7 +49,7 @@ When you send a PR, just make sure that:
 
 * You add valid test cases (Behat and PHPUnit).
 * Tests are green.
-* You make a PR on the related documentation in the [api-platform/doc](https://github.com/api-platform/doc) repository.
+* You make a PR on the related documentation in the [api-platform/docs](https://github.com/api-platform/docs) repository.
 * You make the PR on the same branch you based your changes on. If you see commits
 that you did not make in your PR, you're doing it wrong.
 * Also don't forget to add a comment when you update a PR with a ping to the maintainer (`@dunglas`, `@sroze` or `@theofidry`), so he/she will get a notification.

README.md

@@ -20,8 +20,7 @@ high performance API-first projects. Extend or override everything you want.
 
 ## Documentation
 
-The documentation of API Platform Core is available online and can be edited in
-[its dedicated repository](https://github.com/api-platform/doc/tree/master/core).
+The documentation of API Platform can be browsed [on the official website](https://api-platform.com/docs/).
 
-* [Get started with API Platform](https://github.com/api-platform/docs/blob/master/tutorial/index.md)
-* [A documentation](https://github.com/api-platform/doc/tree/master/core/)
+* [Get started with API Platform](https://api-platform.com/docs/distribution/)
+* [A documentation](https://api-platform.com/docs/)