proposal: update docs for new PAT

[peaceiris]

Checklist

• I am using the latest version of this action.
• I have read the latest README and followed the instructions.
• I have read the latest GitHub Actions official documentation and learned the basic spec and concepts.

Describe your proposal

Introducing fine-grained personal access tokens for GitHub | The GitHub Blog

Describe the solution you'd like

Adding descriptions about scopes with the new PAT.

Describe alternatives you've considered

No response

Additional context

No response

[peaceiris]

Warning

gh: Personal access tokens with fine grained access do not support the GraphQL API (HTTP 401)