Add single command to extract imdb ids from plex database

Import-Plex-Movie-Database-to-Radarr.md

@@ -24,6 +24,16 @@ You'll need to extract this somewhere to use with your DB IDE or open it straigh
 ### Using your Plex database
 The goal here is to obtain all of your IMDB IDs. These are stored as bulky strings in GUID metadata for all movies in the Plex database. An example: `com.plexapp.agents.imdb://tt0000000?lang=en`
 
+#### Linux/OSX one-liner
+
+Update the database location to suit
+
+```bash
+sqlite3 com.plexapp.plugins.library.db "select guid from metadata_items where guid like 'com.plexapp.agents.imdb%';" | grep -P 'tt\d+' -o > movies.txt
+```
+
+#### Or: Step by step
+
 The query I used to get all of my movies:
 
 ```