Remove contribution part from README (#357)

.README.j2

@@ -81,16 +81,6 @@ on the correct GitHub repository matching the add-on.
 
 For a general repository issue or add-on ideas [open an issue here][issue]
 
-## Contributing
-
-This is an active open-source project. We are always open to people who want to
-use the code or contribute to it.
-
-We have set up a separate document containing our
-[contribution guidelines](CONTRIBUTING.md).
-
-Thank you for being involved! :heart_eyes:
-
 ## Adding a new add-on
 
 We are currently not accepting third party add-ons to this repository.

.github/CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing
 
-When contributing to this repository, please first discuss the change you wish
+When contributing to our add-ons, please first discuss the change you wish
 to make via issue, email, or any other method with the owners of this repository
 before making a change.
 
@@ -11,19 +11,17 @@ with the project.
 
 You've found a bug in the source code, a mistake in the documentation or maybe
 you'd like a new feature? You can help us by submitting an issue to our
-[GitHub Repository][github]. Before you create an issue, make sure you search
+GitHub Repository. Before you create an issue, make sure you search
 the archive, maybe your question was already answered.
 
 Even better: You could submit a pull request with a fix / new feature!
 
 ## Pull request process
 
-1. Search our repository for open or closed [pull requests][prs] that relates
+1. Search our repository for open or closed pull requests that relates
    to your submission. You don't want to duplicate effort.
 
 1. You may merge the pull request in once you have the sign-off of two other
    developers, or if you do not have permission to do that, you may request
    the second reviewer to merge it for you.
-
-[github]: https://github.com/hassio-addons/repository/issues
-[prs]: https://github.com/hassio-addons/repository/pulls
+s