build: app version + standalone as only arguments of example app script

[davidlj95]

Currently to create an example app you call the script with the Angular version you want the example app created with. Noice, but that argument is linked to a hardcoded list of example apps.

This could be dynamic. The only thing impeding that rn is the standalone / non standalone argument. Which is what example apps hardcoded list is defined. If adding that as a CLI argument too:

• No need to maintain a hardcoded list of example app configurations. The list of Angular CLI versions in the JSON file would be enough. Hence supporting a new Angular version is easier: a thing less to change
• Standalone / non standalone can be created as wish. So we could create v16 with standalone an non-standalone for instance. Currently it's non standalone only as it's that version's CLI default.

[davidlj95]

Closed by #758