Update bluegreen.md

Author: bcb

docs/bluegreen.md

@@ -12,9 +12,6 @@ stack", now there is:
 3. A front proxy to direct traffic
 4. An external Postgres.
 
-
-
-
 ## 2. Adjust Caddy
 
 ### Name the Caddy containers
@@ -67,14 +64,16 @@ networks:
     external: true
 ```
 
-then in services that need db access:
+Then in services that need db access:
 
 ```yaml title="compose.yaml"
 networks:
-  - default
   - shared
 ```
 
+Move Postgres out of compose.yaml into a shared-compose.yaml, adding the `shared` network:
+
+
 ## 3. Volumes
 
 To share data between the two stacks (uploads, etc.), give volumes explicit