Document TB specific flags available with the start-tor-browser.desktop file on linux

Document all of the useful Tor Browser specific flags that are available with the start-tor-browser.desktop file in GNU/Linux. Maybe this can be filed under something like 'Post-Installation'.

$ ./start-tor-browser.desktop --help
Launching './Browser/start-tor-browser --detach --help'...
.....

Tor Browser Script Options
  --verbose         Display Tor and Firefox output in the terminal
  --log [file]      Record Tor and Firefox output in file (default: tor-browser.log)
  --detach          Detach from terminal and run Tor Browser in the background.
  --register-app    Register Tor Browser as a desktop app for this user
  --unregister-app  Unregister Tor Browser as a desktop app for this user