Request additional shortcut keys

Thank you for this extension! I found it through https://bugzilla.gnome.org/show_bug.cgi?id=733297#c34 . Would you be willing to add a few more keys? My preference would be:

• N => Minimize (changed from current)
• M => Move
• S => Resize
• T => Always on Top

For reference, this Ask Ubuntu answer shows a number of different options. I prefer S for Resize rather than R because I also use Windows, where it is S.

Thank you for considering this request!