Document all hooks and how to use them

Did you verify this is a real problem by searching Stack Overflow and the other open issues in this repo?

Yes, the current hooks documentation does not describe all hooks and use-cases. Also the link in https://github.com/NativeScript/nativescript-cli/blob/master/README.md#extending-the-cli is broken.

Tell us about the problem

We need to document all hooks for CLI and how the plugins and users can get benefit of them.

Tasks:

• Fix the link in https://github.com/NativeScript/nativescript-cli/blob/master/README.md#extending-the-cli
• Document all hooks and when they are executed.
• Describe how to use the hooks and add examples.
• Add tests that verify the examples in the previous step work correctly and will not be broken in future release.

Commencez par la section « Extending the CLI » du README de la CLI et son lien cassé. Dressez l’inventaire des hooks et de leurs points d’exécution, puis documentez leur utilisation et fournissez des exemples pour les plugins et les utilisateurs. Ajoutez des tests qui exécutent les exemples documentés et vérifient qu’ils continuent de fonctionner.