update CONTRIBUTING.md

Author: dzc34

CONTRIBUTING.md

@@ -6,4 +6,19 @@
 You can help in many ways:
 
 * [Fill in a bug report](https://github.com/Asqatasun/Web-Snapshot/issues)
-* [Pull Requests](https://github.com/Asqatasun/Web-Snapshot/pulls) are off course welcome
+* [Pull Requests](https://github.com/Asqatasun/Web-Snapshot/pulls) are off course welcome
+
+
+
+## Fill in bug reports
+
+* [Fill in bug report](https://github.com/Asqatasun/Asqatasun-Jenkins-Plugin/issues)
+* Please do not assign issue to anyone.
+* You may assign an issue to yourself, meaning to others "I'm actually working on this issue".
+* When closing an issue, please *always* add a comment explaining why you are closing it.
+
+
+## Contribution to the code
+
+Please always work on `develop` branch. `Master` is meant to be directly usable in production,
+thus only contains tagged releases.