Add brag-sheet skill — work impact writer for performance reviews

[vidhartbhatia]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• My contribution adds a new skill file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested the skill with GitHub Copilot CLI.

---

Description

brag-sheet is a skill that helps developers write impact-first work entries for performance reviews, backfill work history from git commits/PRs/session logs, and prepare for review discussions.

What it does (standalone)

• Guides users to transform vague descriptions into impact statements ("Did X → Result Y → Evidence Z")
• Backfills from git history, Copilot CLI session-state, and PR history
• Organizes entries by category (pr, bugfix, infrastructure, oncall, etc.)
• Outputs formatted markdown ready for review docs
• Supports STAR format for narrative sections

Full automatic tracking

The skill mentions the copilot-brag-sheet extension (Microsoft org, MIT) for users who want automatic session tracking. The skill is fully useful without the extension.

---

Type of Contribution

• New instruction file.
• New prompt file.
• New agent file.
• New plugin.
• New skill file.
• New agentic workflow.
• Update to existing instruction, prompt, agent, plugin, skill, or workflow.
• Other (please specify):

---

By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

[github-actions]

🔍 Skill Validator Results

✅ All checks passed

Scope	Checked
Skills	1
Agents	1
Total	2
Severity	Count
---	---:
❌ Errors	0
⚠️ Warnings	0
ℹ️ Advisories	0

Summary

Level	Finding
ℹ️	Found 1 skill(s)
ℹ️	[brag-sheet] 📊 brag-sheet: 1,330 BPE tokens [chars/4: 1,338] (detailed ✓), 18 sections, 3 code blocks
ℹ️	✅ All checks passed (1 skill(s))

Full validator output

```text Found 1 skill(s) [brag-sheet] 📊 brag-sheet: 1,330 BPE tokens [chars/4: 1,338] (detailed ✓), 18 sections, 3 code blocks ✅ All checks passed (1 skill(s)) ```

[Copilot]

Pull request overview

Adds a new brag-sheet skill to the skills/ catalog, aimed at helping developers produce impact-first accomplishment entries and backfill work history for performance reviews.

Changes:

• Introduces a new skills/brag-sheet/ skill with guidance for writing “impact-first” entries.
• Adds backfill workflows leveraging git history, Copilot CLI session-state, and GitHub PR history.
• Documents an optional integration with the external copilot-brag-sheet extension for automatic tracking.

[Copilot]

This PR adds a new skill but does not include the generated docs/table updates. Per CONTRIBUTING, after adding a skill you should run npm run skill:validate and npm run build and commit the resulting README table updates (e.g., the skills index in docs/README.skills.md).

[Copilot]

The markdown table under “Transform vague descriptions…” is likely malformed because each row starts with ||, which renders as an empty first column in GitHub-flavored Markdown. Use a single leading | (and keep the same column count) so the table renders as intended.

[Copilot]

The “Categories” table also starts each row with ||, which will create an unintended empty first column and misalign the table. Update the table rows to use the standard single leading | format so it renders correctly.