Env var - PAGE_WATCH_LIMIT enhancements (#4359)

docker-compose.yml

@@ -66,6 +66,10 @@ services:
   #        Absolute minimum seconds to recheck, overrides any watch minimum, change to 0 to disable
   #      - MINIMUM_SECONDS_RECHECK_TIME=3
   #
+  #        Cap the total number of watches this instance will hold - adding more (UI, API, import)
+  #        is refused until one is deleted. Unset means unlimited.
+  #      - PAGE_WATCH_LIMIT=100
+  #
   #        If you want to watch local files file:///path/to/file.txt (careful! security implications!)
   #      - ALLOW_FILE_URI=False
   #