paperless-ngx for use with an proxy like nginx

[BrokenOnedroid]

For use after optional Environment-Vars are possible.

General information on project

This pull request proposes to udapte an rock-on for the following project:

• name: paperless-ngx
• website: https://docs.paperless-ngx.com/
• description: I wanted to add with Update paperless-ngx.json #405 additional environment-vars which are needed if using paperless-ngx with an proxy. Without PAPERLESS_URL and PAPERLESS_CSRF_TRUSTED_ORIGINS an upload not using the ip adress leads into an Http Error 403. See (Forbidden (403) CSRF verification failed. Request canceled. (Verboten (403) CSRF-Verifizierung fehlgeschlagen. Anfrage abgebrochen.) paperless-ngx/paperless-ngx#6216)

Information on docker image

• docker image: https://github.com/paperless-ngx/paperless-ngx
• is an official docker image available for this project?: yes

Checklist

• Passes JSONlint validation
• Entry added to root.json in alphabetical order (for new rock-on only)
• "description" object lists and links to the docker image used
• "description" object provides information on the image's particularities (advantage over another existing rock-on for the same project, for instance)
• "website" object links to project's main website
• Optional environment are possible