Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,6 +1,12 @@
 # Contribution Guidelines
 
-Ensure your pull request to the following guidelines:
+Please note that this project is released with a
+[Contributor Code of Conduct](code-of-conduct.md). By participating in this
+project you agree to abide by its terms.
+
+---
+
+Ensure your pull request adheres to the following guidelines:
 
 - Try to make your pull request as descriptive as possible, especially the title. "Update Readme.md" makes it harder for us to see directly what your pull request is about.
 - Use the KISS principle for descriptions.
@@ -11,3 +17,14 @@ Ensure your pull request to the following guidelines:
 - The application should follow enough of the [KDE Visual Design Group/HIG](https://community.kde.org/KDE_Visual_Design_Group/HIG).
 - Please avoid unmaintained items. 
 - Please label official KDE Projects.
+
+Thank you for your suggestions!
+
+## Updating your PR
+
+A lot of times, making a PR adhere to the standards above can be difficult.
+If the maintainers notice anything that we'd like changed, we'll ask you to
+edit your PR before we merge it. There's no need to open a new PR, just edit
+the existing one. If you're not sure how to do that,
+[here is a guide](https://github.com/RichardLitt/knowledge/blob/master/github/amending-a-commit-guide.md)
+on the different ways you can update your PR so that we can merge it.