Adhere to recommended GitHub community standards

[tobous]

trafficstars

GitHub provides a set of standards that open source projects: https://github.com/saros-project/saros/community

Our GitHub repo should adhere to these standards to make it easier for others to participate.

[m273d15]

Furthermore it is useful (as @tobous mentioned a few days ago) to label issues that can be fixed by beginners.

[m273d15]

The last remaining todo is the creation of the code of conduct. We already talked about the topic and wanted to use the "Contributor Covenant Code of Conduct". Therefore, we have to clarify which email address we want to use.