Contribution guidelines (#101)

* Added first draft

* Added pep ref

* contributing minor adjustments

Co-authored-by: Matteo ℱan <SystemRage@protonmail.com>

docs/Contributing.md

@@ -0,0 +1,15 @@
+# Contributing
+
+You want to improve this project? 
+Awesome! But before you write or modify the existing source code, please note the following guideline:
+
+- Always make sure to add your changes to the wiki.
+- 8-space indentation without tabs.
+- Docstrings as this:
+```python
+    """ This is single line docstring. """
+    """ This is a
+    """ multiline comment.
+```
+- Wrap lines only if really long (it does not matter 79 chars return)
+- For the rest a bit as it comes with a look at [PEP8](https://www.python.org/dev/peps/pep-0008/) :)