add docs: hooks/signals quickstart

[jfunez]

Is your feature request related to a problem? Please describe. We have signals/hooks implemented but poorly documented. Since we have also mkdoc up and running, we must improve the docs

Describe the solution you'd like A quickstart guide should be a good starting point

Describe alternatives you've considered As an alternative an use-case oriented approach should be good too.

Additional context N/A