Add option for adding custom backgrounds

[vanishakesswani]

The app has limited background . A option where you could use image from your system as background for the app will great !

[humdingerb]

It's hidden in the code and not at all ideal. If you put images into /boot/home/config/settings/BeVexed/backgrounds they appear (after a restart) in the menu.

Best would be the option to open a file dialog to add an image that will then be copied to /boot/home/config/settings/BeVexed/backgrounds and a "Manage backgrounds..." that'll open that folder for the user to delete images again.