Improve examples

examples/yii2-postgres.yml

@@ -11,6 +11,8 @@ jobs:
       TEST_DB_USERNAME: postgres
       TEST_DB_PASSWORD: postgres
       DB_CHARSET: utf8
+
+    # Docs: https://docs.github.com/en/actions/using-containerized-services
     services:
       postgres:
         image: postgres:latest
@@ -42,6 +44,11 @@ jobs:
           extensions: mbstring, intl, gd, imagick, zip, dom, pgsql
           coverage: xdebug
 
+      # Local PostgreSQL service in GitHub hosted environments is disabled by default.
+      # If you are using it instead of service containers, make sure you start it.
+      # - name: Start postgresql service
+      #   run: sudo systemctl start postgresql.service
+
       - name: Get composer cache directory
         id: composer-cache
         run: echo "::set-output name=dir::$(composer config cache-files-dir)"