Fix type module not set on script tag in index.html from script 3.

src/steps/03-process-index-html.mjs

@@ -11,7 +11,7 @@ async function step03ProcessIndexHtml() {
     if(!indexHtml.includes("./src/index.js")) {
         indexHtml = indexHtml.replace(
             "<div id=\"root\"></div>",
-            "<div id=\"root\"></div>\n\n    <script src=\"./src/index.jsx\"></script>"
+            "<div id=\"root\"></div>\n\n    <script type=\"module\" src=\"./src/index.jsx\"></script>"
         );
     }