Clarify github workflow

[hanna-212]

Priority (1-3): 1

Impediment:

• The github workflow (especially where to work, where to merge, how to release) is not clear

Notes:

• This issue was mentioned by several people in the retro, but was also clearly visible during sprint review
• The sprint review was chaotic, because people were confused about the merge-process

Solution:

• plan an extra meeting where to discuss and agree on a common worklflow
• clarify on which branch to work
• clarify when to make a pull request
• - clarify where to merge when feature is finished