contributing: Add branching how-to

[wenzeslaus]

A document on how to create a new branch and what needs to be done around that. This complements the release how-to which is about creating releases (tags).

[wenzeslaus]

The commit cab12f1 does not add what it says it adds. The syntax fix is needed, but the information should go to:

## Website Updates

(Here go things like addition of branch creation to history.)

[echoix]

The commit cab12f1 does not add what it says it adds. The syntax fix is needed, but the information should go to:

## Website Updates



(Here go things like addition of branch creation to history.)

We could just clean up the squash message instead of rebasing to achieve the same end goal.

That needed change is in a comment suggestion by Markus Neteler, it just needs to be committed. After that, the PR should be ready.

Having docs is better than no docs, and it's a snapshot of the (then) current knowledge of the workflow. If we find better ways in the future, it can be updated to follow along.

Docs should be fast to merge, especially non end-user addressed ones like this one.

[echoix]

Do you allow me to finish these two things up and merge?

[wenzeslaus]

A fresh pair of eyes here would be great @echoix!

[echoix]

I wrote some comments weeks ago but stayed "pending" since I must have stopped before sending them

[wenzeslaus]

This is now ready for review. Some information might be missing, but we may have a complete picture only after 8.4.0RC1 or even 8.4.0.

[wenzeslaus]

This is now ready to be merged. Please, review.

[echoix]

@veroandreo do you see more typos other than the ones I quickly spotted?

[neteler]

Browsing this on phone (hence limited overview for me), I'd appreciate a hint in the text concerning the cronjob version bump which is needed, too.

The binary build cronjobs are currently failing.

[neteler]

And one more (to be done by @landam):

• wingrass.fsv.cvut.cz/grassXX/addons/ also needs to be updated accordingly.

[echoix]

And one more (to be done by @landam):

• wingrass.fsv.cvut.cz/grassXX/addons/ also needs to be updated accordingly.

There's missing this, but aren't we better to have the currents docs than no updated docs at all (waiting for more than three months for that last edit, if ever we get to it).