Implement check notes directory exists.
On branch master, changes to be committed:
	modified:   config.json   (for some unknown reason; see diff log)
	modified:   quarkExtra.py
	modified:   quarknotemanagermodel.py
Implement navigation using 'Alt+' shortcut keys.
On branch master, changes to be committed:
	modified:   mainwindow.py
Change the name of an action in the 'View' menu.
On branch master, changes to be committed:
	modified:   config.json
	modified:   mainwindow.py