Request: Example of triggering CircleCI when adding a label to a pull request

[kelvintaywl]

Is there an existing issue that is already proposing this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe it

It would be nice to add more examples shown.
In particular, I think it may be nice to show other examples beyond the usual actions.

Describe the solution you'd like

Hence, as an example (no pun intended), it may be nice to share an example of triggering CircleCI pipelines when a PR label is added.

Teachability, documentation, adoption, migration strategy

Shares with users how to set up such cases.

What is the motivation / use case for changing the behavior?

Extend the usage examples of this GitHub Action for triggering CircleCI pipelines.