increase recommended pool size to 16

docker-compose.example.yml

@@ -14,12 +14,12 @@ services:
       REDIS_URL: redis://redis:6379/1
 
       # Database connection string; PostgreSQL is our recommended default
-      DATABASE_URL: postgresql://manyfold:password@postgres/manyfold?pool=5
+      DATABASE_URL: postgresql://manyfold:password@postgres/manyfold?pool=16
       # MySQL / MariaDB also works:
-      # DATABASE_URL: mysql2://manyfold:password@mysql/manyfold?pool=5
+      # DATABASE_URL: mysql2://manyfold:password@mysql/manyfold?pool=16
       # You can also use SQLite if you don't want to run a separate database server.
       # Make sure the specified path is on a persistent volume!
-      # DATABASE_URL: sqlite3:/config/manyfold.sqlite3?pool=5
+      # DATABASE_URL: sqlite3:/config/manyfold.sqlite3?pool=16
 
       # Alternatively, you can set database connection parameters (host, username, etc)
       # in separate variables; see https://manyfold.app/sysadmin/configuration.html.