Adds a toggle button at the top left of fextralife pages that will show/hide the side menu.
目前為 2022-04-03 提交的版本，檢視 最新版本。
這裡只顯示彼此間有代碼差異的版本。 顯示所有版本。
If the page contains the hamburger menu (new drop-down navigation), the script will not run. If the page is resized to enable the side menu once again, this script will do its usual! Hopefully they'll adopt the new drop-down in more pages!
