[CI] Github Actions approval step

[davidcheung]

Following up on #331 (comment)

For both node/go backend/frontned 's Github actions workflow
Unfortunately the Github environments & Protected environments are only available for Public Repos or Github enterprise,

• Document current behavior so users know there's no approval step for Github Actions during the prompt phase instead of finding out it not working as expected maybe here
• keep an eye out for other solutions to provide an approval step using 3rd party actions
• keep an eye out for changes to github environment availability(if it ever changes to allow private repos)
• documenting how to enable protected environments for Public repos