Add links to bluesky account (#6363)

Adds a link from the footer and on the community index page.

src/_includes/page-footer.html

@@ -4,17 +4,22 @@
       <img src="/assets/img/logo/logo-white-text.svg" alt="Dart" width="164">
     </a>
     <div class="footer-social-links">
-      <a href="https://medium.com/dartlang" target="_blank" rel="noopener" title="Medium blog">
+      <a href="https://medium.com/dartlang" target="_blank" rel="noopener" title="Dart's Medium publication">
         <svg>
           <use href="/assets/img/social/medium.svg#medium"></use>
         </svg>
       </a>
-      <a href="https://github.com/dart-lang" target="_blank" rel="noopener" title="GitHub">
+      <a href="https://github.com/dart-lang" target="_blank" rel="noopener" title="Dart's GitHub organization">
         <svg>
           <use href="/assets/img/social/github.svg#github"></use>
         </svg>
       </a>
-      <a href="https://twitter.com/dart_lang" target="_blank" rel="noopener" title="X (Twitter)">
+      <a href="https://bsky.app/profile/dart.dev" target="_blank" rel="noopener" title="Dart's Bluesky profile">
+        <svg>
+          <use href="/assets/img/social/bluesky.svg#bluesky"></use>
+        </svg>
+      </a>
+      <a href="https://twitter.com/dart_lang" target="_blank" rel="noopener" title="Dart's X (Twitter) profile">
         <svg>
           <use href="/assets/img/social/x.svg#x"></use>
         </svg>

src/content/community/index.md

@@ -14,11 +14,14 @@ our [code of conduct](/community/code-of-conduct).
 ## Stay informed
 
 [Dart announce]({{group}}/d/forum/announce)
-: Low traffic announcements of new releases, breaking changes,
+: Low-traffic announcements of new releases, breaking changes,
   and other important news. Recommended!
 
+[@dart.dev](https://bsky.app/profile/dart.dev)
+: Dart's official Bluesky account.
+
 [@dart_lang](https://twitter.com/dart_lang)
-: The official X (Twitter) account.
+: Dart's official X (Twitter) account.
 
 [Dart blog](https://medium.com/dartlang)
 : The latest news and insights from a diverse group of Dart users.