Add recipe for Paperless NG

* First pass at adding recipe for Paperless NG

* Added description of stack contents and a footnote

* Added Paperless entry to mkdocs.yml

* Updated changelog

* Fixed copy/paste error on env file name

* Requested edits

* Added description blurb

* Renamed page and added common link

* Formatting fixes

* Link fixes

* Formatting fix (again)

* Typo

* Requested edits

* Added front matter description

* Removed unused env file from db-backup

_snippets/common-links.md

@@ -19,6 +19,7 @@
 [ombi]:             /recipes/autopirate/ombi/
 [openldap]:         /recipes/openldap/
 [oscarr]:           /recipes/autopirate/oscarr/
+[paperless-ng]:     /recipes/paperless-ng/
 [patreon]:	        https://www.patreon.com/bePatron?u=6982506
 [photoprism]:       /recipes/photoprism/
 [portainer]:        /recipes/portainer/