fix: use absolute volume path for linkwarden postgres data

siklos/linkwarden/docker-compose.yml

@@ -1,13 +1,13 @@
 services:
   postgres:
     image: postgres:16-alpine
-    ports: 
+    ports:
       - "5432:5432"
     restart: always
     environment:
       POSTGRES_PASSWORD: mysecretpassword
     volumes:
-      - ./pgdata:/var/lib/postgresql/data
+      - /srv/docker/linkwarden/pgdata:/var/lib/postgresql/data
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -U postgres"]
       interval: 5s