Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,6 +1,37 @@
 # Contribution Guidelines
 
+Everyone is more than welcome to contribute.
+
+When contributing to this repository, 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.
+
+Please note we have a code of conduct, please follow it in all your interactions
+with the project.
+
+## Issues and feature requests
+
+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
+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
+   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.
+
 ## Requirements to get Pull Requests accepted
 
 * Passes the build (Including Hadolint, shellcheck, markdownlint and others...)
 * Add your changes the the `CHANGELOG.md` and increase the addon version.
+
+[github]: https://github.com/alexbelgium/hassio-addons/issues
+[prs]: https://github.com/alexbelgium/hassio-addons/pulls
+