docs(angular): add cd instruction to move inside workspace directory

npx nx serve angular-store this would not work if the user does not move to the directory first.

docs/shared/tutorials/angular-monorepo.md

@@ -118,6 +118,7 @@ The [`nx.json` file](/reference/nx-json) contains configuration settings for Nx
 To serve your new Angular application, just run:
 
 ```shell
+cd angular-monorepo
 npx nx serve angular-store
 ```