Document how to require approval before a workflow runs

[jsoref]

Code of Conduct

• I have read and agree to the GitHub Docs project's Code of Conduct

What article on docs.github.com is affected?

https://docs.github.com/en/actions/how-tos/write-workflows/choose-when-workflows-run

What part(s) of the article would you like to see updated?

Add a page "Require manual approval for a specific job"

Additional information

• Is it possible to require manual approval for a specific job in GitHub Actions CI/CD? community/community#186436 asked if it was possible
• Is it possible to require manual approval for a specific job in GitHub Actions CI/CD? community/community#186436 (comment) explains that it's possible

1. Visit https://github.com/check-spelling-sandbox/super-duper-fishstick/settings/environments (or similar)
2. Click New environment (or similar)
3. Name it (for my example, I picked spelling)
4. Check Required reviewers
5. Fill in reviewers
   
6. Save
7. Update the workflow to include environment: as in https://github.com/check-spelling-sandbox/super-duper-fishstick/blob/1a6c62c10d1310abfeb58d5b15b73c57b2c768a3/.github/workflows/spelling.yml#L84

---

1. When a workflow run is triggered, it will appear queued:
   
2. Clicking the workflow run will yield something like:
   
3. Clicking Review deployments yields an approval dialog:
   
4. Check the environment and then click Approve and deploy
5. The job will start running:
   

[Sharra-writes]

@jsoref Is this something you're interested in writing, or something you want us to write? Either way, I've asked the rest of the docs team what they think, but it makes a difference whether you're proposing it as an open source project or something we have to find resources for.

[jsoref]

I'm willing to do it, although I'd need advice about how to make the screenshots.

[jsoref]

(Speaking of which, it appears that GitHub ate my screenshots...)