Improve Labeler Action Documentation and Error Handling for Permissions

[chiranjib-swain]

Description:
This pull request updates the GitHub Labeler Action documentation and error handling to clarify required permissions and provide better guidance for resolving issues. The changes include detailed permission requirements, alternative solutions for label creation, and improved error messaging in the code.

Documentation Updates:

• README.md: Expanded the explanation of required permissions for adding and creating labels (pull-requests: write and issues: write), added an example workflow configuration, and provided an alternative for manual label creation to avoid granting issues: write permission.

Error Handling Improvements:

• src/labeler.ts: Enhanced error handling to detect unauthorized errors, provide specific guidance for missing permissions, and improve warning messages with clearer descriptions of required permissions and alternatives.

Related issue:
#870

Check list:

• Mark if documentation changes are required.
• Mark if tests were added or updated to cover the changes.

[Copilot]

Pull Request Overview

This pull request improves the GitHub Labeler Action by enhancing documentation clarity around required permissions and implementing better error handling to guide users when permission issues occur. The changes help users understand the distinction between permissions needed for adding existing labels versus creating new labels.

• Enhanced error handling to detect unauthorized errors and provide specific guidance for missing permissions
• Expanded documentation to clarify permission requirements for different use cases
• Added example workflow configuration and alternative solutions for avoiding issues: write permission

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/labeler.ts	Added specific error detection for 403 unauthorized errors with detailed guidance on required permissions
README.md	Expanded permissions documentation with clearer explanations, example configuration, and manual label creation alternative

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}