Set a standard for commit messages in the Contributing.md file

[Createdd]

To ensure commits that are referencing the issues all commits shall have the format of
#<issue_number> <commit_message>

for example: see this commit

[Createdd]

There is also the possibility to set a git hook as a reminder, but I haven't implemented one in python so far. But this would be the ideal way to do it.

• Add git-hook for commit messages