Add GH action build step to the monorepo examples

[ivan-tymoshenko]

Monorepo apps should be deployed with a github action automatically. For this, we should install dependencies and set env vars for each service in the deploy script.

[simonplend]

I think this is something that probably needs to be handled by create-platformatic when creating a new Runtime project and when adding services. See: platformatic/platformatic#1229