Improve README Generation Workflow to Update Within PRs

[corylanou]

This PR modifies the Hype README generation workflow to be more integrated with our development process:

Key Changes

• Changes workflow trigger from push to main to pull_request events
• README updates now happen within PRs instead of creating separate PRs
• Only commits README changes when actual updates are needed
• Adds proper permissions for GitHub Actions bot
• Simplifies checkout process and git configuration

Benefits

• README changes are now coupled with the code changes that triggered them
• Easier review process as all changes are visible in the same PR
• Eliminates extra PRs just for README updates
• Respects branch protection rules by working within PR workflow
• More efficient by only committing when actual changes exist

Technical Details

• Triggers on PR events: opened, synchronize, and reopened
• Uses GitHub Actions bot identity for commits
• Checks for actual README changes before committing