Update github/workflows/drupal.yaml

Co-authored-by: Ture Gjørup <[email protected]>

Author: rimi-itk

github/workflows/drupal.yaml

@@ -7,7 +7,9 @@
 ###
 ### 1. A docker compose service named `phpfpm` can be run and `composer` can be
 ###    run inside the `phpfpm` service.
-### 2. The Drupal site can be installed from existing config.
+### 2. The docker setup contains a database container and other the dependent services and the
+            default settings match connection credentials for these services.
+### 3. The Drupal site can be installed from existing config.
 
 name: Drupal