docs: Add a nginx.conf.standalone config snippet
docs: Add a nginx.conf.standalone config snippet

Add a config snippet for running nginx as the main web server without
using a proxy.

Signed-off-by: Andrew Clayton <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@opentechlabs.co.uk>

ac000/receiptomatic