docs: fix shell language name in migration guide

docs/en/UI/Angular/Migration-Guide-v3.md

@@ -10,7 +10,7 @@ The new ABP Angular UI is based on Angular 10 and TypeScript 3.9, and we have dr
 
 Open a terminal at your root folder and run the following command:
 
-```sh
+```shell
 yarn ng update @angular/cli @angular/core --force
 ```
 
@@ -26,7 +26,7 @@ On the other hand, it would be better if you check which packages to update firs
 
 When Angular reports the packages above, your command would look like this:
 
-```sh
+```shell
 yarn ng update @angular/cli @angular/core ng-zorro-antd --force
 ```