cheatsheet in help

[ReimarBauer]

We have a lot keys added to the controls of the views.

It may be good to give an overview in the documentation or in the app itselfs.

@joernu76 what do you think about this?

[joernu76]

Mmmh. Not many, which are not pretty standard.
We should go through all the tooltips to make sure, they are correct and offer the shortcut, if available.