Add LINKED_CARDS_ENABLED env var

docker-compose.yml

@@ -559,7 +559,9 @@ services:
       # example : LOGOUT_ON_MINUTES=55
       #- LOGOUT_ON_MINUTES=
       #-------------------------------------------------------------------
-
+      # LINKED_CARDS_ENABLED : Enable or not the linked cards feature
+      # example : LINKED_CARDS_ENABLED=false
+      - LINKED_CARDS_ENABLED=true
     depends_on:
       - wekandb