Bring back some of the contribution guidelines
Bring back some of the contribution guidelines

We had a couple of create issue->immediately send PR submissions
again. Let's explain a bit more what we expect from people.

differentreality/osem,AndrewKvalheim/osem,openSUSE/osem,AndrewKvalheim/osem,differentreality/osem,openSUSE/osem,differentreality/osem,hennevogel/osem,SeaGL/osem,hennevogel/osem,SeaGL/osem,SeaGL/osem,hennevogel/osem,openSUSE/osem,hennevogel/osem,differentreality/osem,AndrewKvalheim/osem