docs: added missing sub_filters in nginx subpath (#1052)

* Update reverse-proxy.mdx

Fix posters not showing up when using sub-folder (at least with NPM)

* Update docs/extending-jellyseerr/reverse-proxy.mdx

Added `avatarproxy` support

Co-authored-by: Gauthier <[email protected]>

---------

Co-authored-by: Gauthier <[email protected]>

Author: C4J3

docs/extending-jellyseerr/reverse-proxy.mdx

@@ -95,6 +95,8 @@ location ^~ /jellyseerr {
     sub_filter '/api/v1' '/$app/api/v1';
     sub_filter '/login/plex/loading' '/$app/login/plex/loading';
     sub_filter '/images/' '/$app/images/';
+    sub_filter '/imageproxy/' '/$app/imageproxy/';
+    sub_filter '/avatarproxy/' '/$app/avatarproxy/';
     sub_filter '/android-' '/$app/android-';
     sub_filter '/apple-' '/$app/apple-';
     sub_filter '/favicon' '/$app/favicon';