docs: release notes for the vscode extension 21.0.1 release

Author: atscott

vscode-ng-language-service/CHANGELOG.md

@@ -1,3 +1,11 @@
+## 21.0.1 (2025-12-17)
+
+- fix(language-service): Prevent language service from crashing on suggestion diagnostic errors (5047be4bc1)[https://github.com/angular/angular/commit/5047be4bc1c6f6016263703c743f8033f669f0ee]
+- fix(language-service): avoid interpolation highlighting inside @let (e0694df3ec)[https://github.com/angular/angular/commit/e0694df3eccae3d31a4ea537dffe1db1368ef34a]
+- fix(vscode-extension): Show warning if multiple versions of Angular are detected in workspace (a41b0ce025)[https://github.com/angular/angular/commit/a41b0ce02528c27e4804bcd39a61c932503bae61]
+
+<!-- CHANGELOG SPLIT MARKER -->
+
 ## 21.0.0 (2025-11-18)
 
 - fix(language-service): address potential memory leak during project creation (89095946cf)[https://github.com/angular/angular/commit/89095946cff051c5613b8f54ec722d08cd47c709]