chore: adjust GitHub template envinfo command (#6359)

Author: mxschmitt

.github/ISSUE_TEMPLATE/bug.md

@@ -15,7 +15,7 @@ assignees: ''
 - Extra: [any specific details about your environment]
 
 <!-- CLI to auto-capture this info -->
-<!-- npx envinfo --preset playwright -->
+<!-- npx envinfo --preset playwright --markdown -->
 
 **Code Snippet**