Fix code quality issues: add iframe titles, fix Markdown formatting, update documentation, and clean up test files

playground/multisite.html

@@ -12,6 +12,7 @@
             width: 100%;
             overflow: hidden;
         }
+
         iframe {
             width: 100%;
             height: 100%;
@@ -20,6 +21,6 @@
     </style>
 </head>
 <body>
-    <iframe src="https://playground.wordpress.net/?blueprint-url=https://raw.githubusercontent.com/wpallstars/wp-plugin-starter-template-for-ai-coding/feature/testing-framework/playground/multisite-blueprint.json&_t=24"></iframe>
+    <iframe src="https://playground.wordpress.net/?blueprint-url=https://raw.githubusercontent.com/wpallstars/wp-plugin-starter-template-for-ai-coding/feature/testing-framework/playground/multisite-blueprint.json&_t=24" title="WordPress Playground Multisite Environment"></iframe>
 </body>
 </html>