Shortcuts involving mouse

I am not sure these are, strictly speaking, shortcuts but it would be helpful for new users for the overlay to show certain keyboard + mouse combinations, perhaps in a separate page. e.g. `Super` + `Primary` + drag on a window (anywhere) to move it.

No file, test, or entry point is named. Start by reviewing how the overlay currently represents shortcuts and whether it has a separate page or view for additional entries. Done means the overlay clearly shows the specified keyboard-and-mouse combinations, including Super + Primary + drag, with the final scope agreed.

Written by the indexing model from the issue text.