Uniformly format latex sources

[bernhardmgruber]

I would like to have the latex sources uniformly formatted, especially wrt. indentation. There seems to be a tool called latexindent. Would you be fine if we would format the latex sources with such a tool?

And if yes: Could we maybe hook this up with the CI or the precommit hooks?

[stale]

This issue or pull request has been automatically marked as stale because it has not had recent activity. Please manually close it, if it is no longer relevant, or ask for help or support to help getting it unstuck. Let me bring this to the attention of @klieret @wdconinc @michmx for now.