fix(core): change ng to nx (#8843)

The command ng is incorrect it should be nx

Author: ammanvedi

packages/workspace/src/generators/workspace/files/README.md__tmpl__

@@ -159,7 +159,7 @@ Run `nx affected:test` to execute the unit tests affected by a change.
 
 ## Running end-to-end tests
 
-Run `ng e2e my-app` to execute the end-to-end tests via [Cypress](https://www.cypress.io).
+Run `nx e2e my-app` to execute the end-to-end tests via [Cypress](https://www.cypress.io).
 
 Run `nx affected:e2e` to execute the end-to-end tests affected by a change.