Add APP_LOGGING
Add APP_LOGGING

This will add an variable for logging types to make it easier to define outside via .env.

Signed-off-by: solidnerd <387783e228a6a981e052f1b545e5a6a45a21cc6e@mietz.io>

BookStackApp/BookStack,oomba/the-loud-cartographer,Abijeet/BookStack,BookStackApp/BookStack,Abijeet/BookStack,oomba/the-loud-cartographer,Abijeet/BookStack,BookStackApp/BookStack,oomba/the-loud-cartographer