docs(plex): add some Plex integration related documentation (#1662)

* docs(plex): add some Plex integration related documentation

* docs(plex): clarify watchlist auto-request permission requirements

* fix(docs): missing newline

docs/using-jellyseerr/plex/index.md

@@ -0,0 +1,36 @@
+---
+title: Overview
+description: Learn about Jellyseerr's Plex integration features
+sidebar_position: 1
+---
+
+# Plex Features Overview
+
+Jellyseerr provides integration features that connect with your Plex media server to automate media management tasks.
+
+## Available Features
+
+- [Watchlist Auto Request](./plex/watchlist-auto-request) - Automatically request media from your Plex Watchlist
+- More features coming soon!
+
+## Prerequisites
+
+:::info Authentication Required
+To use any Plex integration features, you must have logged into Jellyseerr at least once with your Plex account.
+:::
+
+**Requirements:**
+- Plex account with access to the configured Plex server
+- Jellyseerr configured with Plex as the media server
+- User authentication via Plex login
+- Appropriate user permissions for specific features
+
+## Getting Started
+
+1. Authenticate at least once using your Plex credentials
+2. Verify you have the necessary permissions for desired features
+3. Follow individual feature guides for setup instructions
+
+:::note Server Configuration
+Plex server configuration is handled by your administrator. If you cannot log in with your Plex account, contact your administrator to verify the server setup.
+:::