docs: Add clarification comment to issue-comment.yml workflow

[bhouston]

Description

This PR adds documentation to the issue-comment.yml workflow file to clarify its behavior. The workflow is correctly triggering on all issue comments and then evaluating the condition to determine if the job should run.

Changes

• Added a comment block at the top of the workflow file explaining that:
  • The workflow is triggered on all issue comments
  • The job only runs if the comment contains '/mycoder' and is from the authorized user
  • The workflow will appear in GitHub Actions logs for all comments, but will exit early if conditions aren't met

Related Issues

Fixes #232

Testing

No functional changes were made, only documentation was added.