README: minor tweak to XSD validate code sample

jrfnl · jrfnl · commit 38690dba52e7 · 2025-05-17T11:34:22.000+02:00
diff --git a/README.md b/README.md
@@ -217,6 +217,8 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
+      ... # (install PHP, run composer)
+
       - name: Validate docs against schema
         uses: phpcsstandards/xmllint-validate@v1
         with:
