👥 Create CONTRIBUTING.md

Author: MiWeiss

CONTRIBUTING.md

@@ -0,0 +1,20 @@
+Thanks heaps for being interested in contributing to python-bibtexparser.
+
+We are always looking for people to improve the library. Contributions include, but are not limited to:
+
+1. Opening well described issues for bugs or feature requests.
+2. Providing bugfixing PRs
+3. Implementing any of the issues or continuing any of the PRs labelled with `needs help` or `good first issue`.
+
+Some guidelines:
+
+1. Be nice! Were all doing this in our free time; no one is obligated to do anything.
+2. Add sufficient tests to your PRs 
+3. Document your code.
+4. Don't hesitate to ask questions.
+
+Also note that there are currently two independent "default" branches: 
+First, `master`, where we maintain a stable `v1.x` and where we merge almost only backwards-compatible bugfixes.
+Second, `v2` where we work on a full re-implementation of the library. 
+
+Issues targeting the `v2` branch are labelled `v2`.