Enhance the markers view in the clip properties with keyboard support
In the markers view of the clip properties, it would be possible to operate more with keyboard.
The only working shortcut is delete (DEL), but why not have a shortcut for edit marker (like F2) and add marker (like +)? Also, it would be nice to show the shortcuts as tooltips with the buttons below the list.
The focus should also go to the list when the the view is activated.