chore(vscode): recommend Markdown all in one

.vscode/extensions.json

@@ -5,6 +5,7 @@
     "vitest.explorer",
     "ms-playwright.playwright",
     "tobermory.es6-string-html",
-    "dbaeumer.vscode-eslint"
+    "dbaeumer.vscode-eslint",
+    "yzhang.markdown-all-in-one"
   ]
 }