Keybinds hint bar at the bottom

[goosethedev]

Checklist

• I've looked through the documentation and existing open issues for similar feature requests.

Describe the feature request

It would be easier to use and remember the keybinds with a bar that hints you what ones you can use at the selected widget, like GitUI:

[ClementTsang]

Hm, I've thought about something like this - I guess I could do something like I do with the frozen indicator, and make it controllable.