Update API homepage to link to dart.dev, not dartlang.org

Closes #37026
https://github.com/dart-lang/sdk/pull/37026

GitOrigin-RevId: 386b573c71dbb7ff22ca0afa344258ee24dd6663
Change-Id: I6e3761bb03220c886f8ee9e379486b7903fb37bd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103220
Reviewed-by: Kevin Moore <kevmoo@google.com>
Commit-Queue: Kevin Moore <kevmoo@google.com>
diff --git a/sdk/api_readme.md b/sdk/api_readme.md
index 3e5990dd..2f51f7e 100644
--- a/sdk/api_readme.md
+++ b/sdk/api_readme.md
@@ -16,15 +16,15 @@
 ```
 
 You can install more libraries using the
-[pub package manager](https://www.dartlang.org/tools/pub).
+[pub package manager](https://dart.dev/guides/packages).
   
 The main site for learning and using Dart is
-[www.dartlang.org](https://www.dartlang.org). Check out these pages:
+[dart.dev](https://dart.dev). Check out these pages:
   
-  * [Get started](https://www.dartlang.org/guides/get-started)
-  * [Language tour](https://www.dartlang.org/guides/language/language-tour)
-  * [Library tour](https://www.dartlang.org/guides/libraries/library-tour)
-  * [Sample code](https://www.dartlang.org/samples)
+  * [Platforms](https://dart.dev/platforms)
+  * [Language tour](https://dart.dev/guides/language/language-tour)
+  * [Library tour](https://dart.dev/guides/libraries/library-tour)
+  * [Sample code](https://dart.dev/samples)
   
 This API reference is automatically generated from source code in the [Dart
 SDK project](https://github.com/dart-lang/sdk).