Fix overseerr link and description (#22)

* Correct Broken link to Overseerr and add link to git repo for parent.

* Update description with more detail

Author: thinko

overseerr/.README.j2

@@ -8,12 +8,13 @@ Request management and media discovery tool for the Plex ecosystem.
 
 ## About
 
-[Overseerr] is a multi-platform binary newsgroup downloader. The program works in
-the background and simplifies the downloading verifying and extracting of files
-from [Usenet].
+[Overseerr] is a request management and media discovery platform for the [Plex] media platform. Overseerr
+integrates into a Plex environment as well as [Radarr]/[Sonarr] for Movie and PVR/TV content management.
 
-[Overseerr]: https://overseerr.org/
-[Usenet]: http://en.wikipedia.org/wiki/Usenet
+[Overseerr]: https://overseerr.dev/
+[Plex]: https://plex.tv/
+[Radarr]: https://radarr.video/
+[Sonarr]: https://sonarr.tv/
 
 {% if channel == "edge" %}
 ## WARNING! THIS IS AN EDGE VERSION!