Tabs Numbering per andreczw

Firefox add-on that numbers each tab in order to facilitate tab-switching to users who use keyboard shortcuts. Thought for i3 file manager users.
It doesn't work on certain tabs like "new tab", but i think there's nothing i can do about those tabs.
(This is just a small side project that i'll come back to whenever i have some spare time).
Safe to use, no malicious code.
You can also check the code out on my github repository: https://github.com/siizx/firefox_tabsnumbering
- Remember:
In Firefox, the keyboard shortcuts Alt + 1 through Alt + 8 allow you to switch to the corresponding tab from left to right. Alt + 9 will switch to the last tab, regardless of how many tabs are open.
There’s no built-in keyboard shortcut to directly switch to tabs numbered 10 and above. If you need to navigate through a large number of tabs, you can use the following shortcuts:

Ctrl + Tab: This will switch to the next tab.
Ctrl + Shift + Tab: This will switch to the previous tab.