Enhancement: Add conventional commit guidance to finishing-a-development-branch PR template

[holstein13]

Summary

The finishing-a-development-branch skill creates PRs with a basic template:

## Summary
<2-3 bullets of what changed>

## Test Plan
- [ ] <verification steps>

This template could be enhanced to support projects using conventional commits and semantic versioning.

Proposed Enhancement

Update the PR template in Option 2 (Push and Create PR) to include:

1. Conventional commit guidance for the PR title
2. Version impact indicator
3. Breaking change checkbox

Suggested Template

## Summary
<2-3 bullets of what changed>

## Version Impact
<!-- Check ONE that applies -->
- [ ] `fix:` - Bug fix (PATCH: x.x.X)
- [ ] `feat:` - New feature (MINOR: x.X.0)
- [ ] `feat!:` - Breaking change (MAJOR: X.0.0)
- [ ] `docs:` / `chore:` - No version bump

## Breaking Changes
<!-- If this is a breaking change, describe what breaks -->
N/A

## Test Plan
- [ ] <verification steps>

Benefits

• Guides contributors to use proper commit message prefixes
• Makes version impact visible in PR review
• Helps maintainers identify breaking changes before merge
• Works seamlessly with standard-version, semantic-release, and similar tools

Context

Many projects use conventional commits with automated version bumping. This enhancement would help Claude assist users in maintaining proper commit conventions without requiring a separate .github/PULL_REQUEST_TEMPLATE.md file in each project.

Alternatives Considered

1. Project-specific PR templates - Works but requires per-project setup
2. Separate skill for conventional commits - Could complement this enhancement

Would love to hear thoughts on whether this fits the superpowers philosophy or if there's a better approach.