Move OnlyOffice to be its own configuration again. Add sourcing of DNS settings so that local traffic routes correctly.

Config/OnlyOffice/docker-compose.yml

@@ -0,0 +1,20 @@
+# 2023-07-25
+# OnlyOffice server, primarily used for Nextcloud.
+
+version: '3'
+
+services:
+  app:
+    container_name: oo-app
+    image: onlyoffice/documentserver
+    restart: always
+    ports:
+      - 8000:80
+      - 4443:443
+    environment:
+      - JWT_SECRET=abc123
+    env_file:
+      - ../../dns.env
+    dns:
+      - $DNS1
+      - $DNS2