Sum Tabs wót Timvde

This is a simple add-on providing a button with the number of tabs in the current window. If you click it, a pop-up opens, showing the total number of tabs in all windows too.

Known limitations:
- The badge gets updated globally, so it cannot show the number of tabs in two windows at once. In inactive windows, the number of tabs in the active window is shown. If no window is active, it is the number of the last active window instead.

Credits:
- Icon: Bert Van de Poel (CC-BY-SA)
- Name: Mardeg