Simplify index.mst to a single div to insert the editor

packages/node_modules/@node-red/editor-api/lib/editor/theme.js

@@ -169,6 +169,9 @@ module.exports = {
                 }
             }
         }
+        themeApp.get("/", function(req,res) {
+            res.json(themeContext);
+        })
 
         if (theme.hasOwnProperty("menu")) {
             themeSettings.menu = theme.menu;