docs: update PostgreSQL volume path in docker-compose (#242)

According to: docker-library/postgres#1259

The postgres data volume should no longer contain /data

Author: cibomahto

src/content/docs/setup/docker-start-to-finish.mdoc

@@ -51,7 +51,7 @@ services:
             POSTGRES_USER: vikunja
 
         volumes:
-            - ./db:/var/lib/postgresql/data
+            - ./db:/var/lib/postgresql
         restart: unless-stopped
         healthcheck:
             test: ["CMD-SHELL", "pg_isready -h localhost -U $$POSTGRES_USER"]

src/content/docs/setup/full-docker-example.mdoc

@@ -142,7 +142,7 @@ services:
       POSTGRES_PASSWORD: changeme
       POSTGRES_USER: vikunja
     volumes:
-      - ./db:/var/lib/postgresql/data
+      - ./db:/var/lib/postgresql
     restart: unless-stopped
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -h localhost -U $$POSTGRES_USER"]
@@ -198,7 +198,7 @@ services:
       POSTGRES_PASSWORD: changeme
       POSTGRES_USER: vikunja
     volumes:
-      - ./db:/var/lib/postgresql/data
+      - ./db:/var/lib/postgresql
     restart: unless-stopped
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -h localhost -U $$POSTGRES_USER"]
@@ -256,7 +256,7 @@ services:
       POSTGRES_PASSWORD: changeme
       POSTGRES_USER: vikunja
     volumes:
-      - ./db:/var/lib/postgresql/data
+      - ./db:/var/lib/postgresql
     restart: unless-stopped
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -h localhost -U $$POSTGRES_USER"]