git: Implement pre-commit hooks

[nicu1989]

It would be nice to have some checks done also at commit level, before push.
At least the gitlint would be good but also format check.

Also document the necessary steps required by contributor(if any).

[MaximilianSoerenPollak]

Pre-push makes sense, pre-commit doesn't in my opinion, as then it would run even when you aren't 'ready' for it.
If you have it commited then I guess you 'signal' that at least for now you are done working on it and the stuff could run.

Edit: I guess the hook would be called commit-msg for the git lint stuff, and for the rest probably something else.

Relevant url: git docs

[AlexanderLanin]

Hint: pre-commit.com is nicer than creating git-commands manually

Open points:

• pre commit or pre push?
• what exactly do we check?

Note: specifically, for gitlint see issue TODO