add correct networking setup for plausible to work with nginx

plausible.yaml

@@ -1,14 +1,24 @@
 version: "3.3"
+
+networks:
+  frontend:
+    external: true
+  plausible:
+
 services:
   mail:
     image: bytemark/smtp
     restart: always
+    networks:
+      - plausible
 
   plausible_db:
     # Plausible v2.0.0 was tested against PostgreSQL versions 12, 13, and 14
     # https://github.com/plausible/analytics/blob/v2.0.0/.github/workflows/elixir.yml#L16
     image: postgres:14-alpine
     restart: always
+    networks:
+      - plausible
     volumes:
       - /hdd/plausible/db_data:/var/lib/postgresql/data
     environment:
@@ -17,6 +27,8 @@ services:
   plausible_events_db:
     image: clickhouse/clickhouse-server:23.3.7.5-alpine
     restart: always
+    networks:
+      - plausible
     volumes:
       - /hdd/plausible/event_data:/var/lib/clickhouse
       - /hdd/plausible/clickhouse/clickhouse-config.xml:/etc/clickhouse-server/config.d/logging.xml:ro
@@ -34,6 +46,9 @@ services:
       - plausible_db
       - plausible_events_db
       - mail
+    networks:
+      - frontend
+      - plausible
     environment:
       - BASE_URL=https://plausible.nauen-it.de
       - SECRET_KEY_BASE=cwLeX7x0f7E50Q9+ANihxd6T7vbHUloZQ+70ex+eEbydJITKCxf+piXk+S1LeMP+