[3.2] Add banner for release and blog post (#5353)

Co-authored-by: Parker Lougheed <[email protected]>

src/_includes/banner.html

@@ -1,7 +1,9 @@
 <div class="banner">
   <p class="banner__text">
-    Dart 3.1 is out, with updates supporting the new features from Dart 3.0.
+    Check out the
+    <a href="https://medium.com/dartlang/dart-3-2-c8de8fe1b91f" class="no-automatic-external">Dart 3.2 blog post</a>!
     <br>
-    <a href="https://medium.com/dartlang/a1f4b3a7cdda" class="no-automatic-external">Check out the blog post</a>!
+    This release brings enhancements to type promotion, interop capabilities,
+    DevTools, and more.
   </p>
 </div>

src/guides/language/evolution.md

@@ -43,6 +43,7 @@ environment:
 
 ### Dart 3.2
 _Released 15 November 2023_
+| [Dart 3.2 announcement](https://medium.com/dartlang/dart-3-2-c8de8fe1b91f)
 
 Dart 3.2 added enhancements to flow analysis, including:
 
@@ -83,8 +84,6 @@ Dart 3.2 added enhancements to flow analysis, including:
   where the value being matched against throws an exception.
 
 
-
-
 ### Dart 3.1
 _Released 16 August 2023_
 | [Dart 3.1 announcement](https://medium.com/dartlang/dart-3-1-a-retrospective-on-functional-style-programming-in-dart-3-a1f4b3a7cdda)