Add note re: type="module" to getting-started.md (#418)

src/i18n/en/docs/getting_started.md

@@ -39,6 +39,7 @@ Next, create an index.html and index.js file.
 </body>
 </html>
 ```
+NB: Parcel converts JS assets to ES5, which won't run in in the context of a `<script type="module">` tag, so just use plain `<script>` tags with no `type` attribute in your source HTML.
 
 ```javascript
 console.log('hello world')