fix: migrate untranslated files

Author: lacolaco

adev-ja/src/content/events/v21.md

@@ -1,29 +1,37 @@
-![A retro 8-bit, pixel art style graphic announcing the upcoming release of Angular v21. The large, gradient 'v21' text dominates the frame. Next to it, in smaller text, are the words 'The Adventure Begins' and the release date '11-20-2025' inside a pink pixelated box. The Angular logo is in the bottom right corner.](assets/images/angular-v21-hero.jpg 'Angular v21 Hero Image')
+![A retro 8-bit, pixel art style graphic announcing the upcoming release of Angular v21. The large, gradient 'v21' text dominates the frame. Next to it, in smaller text, are the words 'The Adventure Begins' and the release date '11-20-2025' inside a pink pixelated box. The Angular logo is in the bottom right corner.](assets/images/v21-event/angular-v21-hero.jpg 'Angular v21 Hero Image')
 
 # Angular v21: The Adventure Begins
 
+## Release Blog
+
 **Angular v21 is live**: check out the [v21 release blog](http://goo.gle/angular-v21-blog) to learn about all of the amazing new features coming your way.
 
-## Save the Date November 20, 2025
+## Experience the v21 Release
+
+Explore the Angular v21 release with this interactive game world. Curious how we made it? Click the `Show Code` button below to view the source code for this Angular app.
 
-<docs-pill-row>
-  <docs-pill href="https://calendar.google.com/calendar/render?action=TEMPLATE&text=Angular+v21+Launch&dates=20251120T170000Z/20251120T173000Z&details=Get+ready+for+the+future+of+web+development+with+Angular.+Tune+in+https://goo.gle/angular-v21&location=https://goo.gle/angular-v21" title="Add to Google Calendar"/>
-  <docs-pill href="/assets/others/angular-v21-release.ics" title="Add to iCal/Outlook" download="angular-v21-release.ics" target="_blank" />
-</docs-pill-row>
+<docs-code preview hideCode header="v21 Game World" path="adev/src/content/examples/v21-game-world/src/app/app.ts" />
 
-<hr/>
+## Angular v21 Developer Event [Full Version]
 
-Join the Angular team this November for a brand new release adventure. With modern AI tooling, performance updates and more, Angular v21 delivers fantastic new features to improve your developer experience. Whether you’re creating AI-powered apps or scalable enterprise applications, there has never been a better time to build with Angular.
+Angular v21 is being delivered to you as a brand new release adventure. With modern AI tooling, performance updates and more, Angular v21 delivers fantastic new features to improve your developer experience. Whether you’re creating AI-powered apps or scalable enterprise applications, there has never been a better time to build with Angular.
 
 🔥 What's coming in v21
 
 - New Angular MCP Server tools to improve AI-powered workflows and code generation
 - Your first look at Signal Forms, our new streamlined, signal-based approach to forms in Angular
-- Exciting new details about the Angular ARIA package
-
-That’s just a taste of what’s coming in our upcoming major release event. You won't want to miss it.
-
-<docs-pill-row>
-  <docs-pill href="https://calendar.google.com/calendar/render?action=TEMPLATE&text=Angular+v21+Launch&dates=20251120T170000Z/20251120T173000Z&details=Get+ready+for+the+future+of+web+development+with+Angular.+Tune+in+https://goo.gle/angular-v21&location=https://goo.gle/angular-v21" title="Add to Google Calendar"/>
-  <docs-pill href="/assets/others/angular-v21-release.ics" title="Add to iCal/Outlook" download="angular-v21-release.ics" target="_blank" />
-</docs-pill-row>
+- Exciting new details about the Angular Aria package
+
+<div style="display: block; width: 80%; margin: 0 auto; margin-top: 20px;">
+  <iframe
+    credentialless
+    width="560"
+    height="315"
+    src="https://www.youtube.com/embed/DDAHORVzQ5g?si=B9Uv5vXzIKJfcLGr"
+    title="YouTube video player"
+    frameborder="0"
+    allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share"
+    referrerpolicy="strict-origin-when-cross-origin"
+    allowfullscreen
+  ></iframe>
+</div>