Create CONTRIBUTING.md

Author: haimkastner

CONTRIBUTING.md

@@ -0,0 +1,10 @@
+# Contributing to the casanet project.
+
+:+1::tada: First off, thanks for taking the time to contribute! :tada::+1:
+
+## Getting started
+
+- Create a new branch and commit changes into it.
+- Open a PR to the `development` branch (not master).
+
+Thank a lot!