Documented new (optional) CSS solution that allows you to use the native min/max/close buttons

Added keyboard support with "Ctrl+Alt+T" as the default

- Added Firefox 133 userChrome.css change instructions to be displayed after the addon updates
- Added a checkbox to allow users to disable showing the installation instructions after an update until another change is needed
- Added prism.js library to support CSS color highlighting
- Changed much of the instructions to have better formatting
- Added PC and Mac specific instructions when creating userChrome.css for the first time
- Removed prism.js, kept prism.css, and hard-coded CSS styling
- Received a "Unsafe assignment to innerHTML" (from AMO) for prism.js I will need to find a workaround before including

Fixed a bug to properly show/hide the native tab bar when either dragging a tab to create a new window or if you use CTRL+N to create a new window.

Changed delimiter from "XXX" to " " to avoid display issues.