feat: add Protobuf and gRPC API review skill 🤖🤖🤖 (#3085)

* feat: add protobuf and gRPC API review skill

* fix: use accepted spelling in review skill

* docs: clarify per-method authorization guidance

docs/README.skills.md

@@ -331,6 +331,7 @@ See [CONTRIBUTING.md](../CONTRIBUTING.md#adding-skills) for guidelines on how to
 | [premium-frontend-ui](../skills/premium-frontend-ui/SKILL.md)<br />`gh skills install github/awesome-copilot premium-frontend-ui` | A comprehensive guide for GitHub Copilot to craft immersive, high-performance web experiences with advanced motion, typography, and architectural craftsmanship. | None |
 | [project-workflow-analysis-blueprint-generator](../skills/project-workflow-analysis-blueprint-generator/SKILL.md)<br />`gh skills install github/awesome-copilot project-workflow-analysis-blueprint-generator` | Comprehensive technology-agnostic prompt generator for documenting end-to-end application workflows. Automatically detects project architecture patterns, technology stacks, and data flow patterns to generate detailed implementation blueprints covering entry points, service layers, data access, error handling, and testing approaches across multiple technologies including .NET, Java/Spring, React, and microservices architectures. | None |
 | [prompt-optimizer](../skills/prompt-optimizer/SKILL.md)<br />`gh skills install github/awesome-copilot prompt-optimizer` | Turn any rough prompt, half-formed idea, or task description into a finished, ready-to-send prompt optimized for any LLM model inside a chat interface — NOT the API. Use this skill whenever the user wants to write, rewrite, optimize, improve, sharpen, or polish a prompt for chat. Trigger phrases include "rewrite this prompt", "make this a better prompt", "optimize this prompt", "turn this into a prompt", "help me prompt this", "draft a prompt that...", "I want to ask...", or whenever the user pastes a draft prompt and asks for improvements. Also trigger when the user describes a task they plan to send to an LLM model and clearly wants a reusable, well-structured prompt rather than a direct answer. The output is always a single, copy-pasteable prompt in a code block that the user sends as-is — never a template with placeholders. | None |
+| [protobuf-grpc-api-review](../skills/protobuf-grpc-api-review/SKILL.md)<br />`gh skills install github/awesome-copilot protobuf-grpc-api-review` | Review Protocol Buffer (.proto) and gRPC API changes for wire and JSON compatibility, safe schema evolution, rollout hazards, and RPC contract quality. Use when reviewing proto diffs, adding or changing messages and services, planning migrations, or diagnosing cross-version failures. | `references/grpc-contract-review.md`<br />`references/protobuf-compatibility.md` |
 | [publish-to-pages](../skills/publish-to-pages/SKILL.md)<br />`gh skills install github/awesome-copilot publish-to-pages` | Publish presentations and web content to GitHub Pages. Converts PPTX, PDF, HTML, or Google Slides to a live GitHub Pages URL. Handles repo creation, file conversion, Pages enablement, and returns the live URL. Use when the user wants to publish, deploy, or share a presentation or HTML file via GitHub Pages. | `scripts/convert-pdf.py`<br />`scripts/convert-pptx.py`<br />`scripts/publish.sh` |
 | [pytest-coverage](../skills/pytest-coverage/SKILL.md)<br />`gh skills install github/awesome-copilot pytest-coverage` | Run pytest tests with coverage, discover lines missing coverage, and increase coverage to 100%. | None |
 | [python-azure-iot-edge-modules](../skills/python-azure-iot-edge-modules/SKILL.md)<br />`gh skills install github/awesome-copilot python-azure-iot-edge-modules` | Build and operate Python Azure IoT Edge modules with robust messaging, deployment manifests, observability, and production readiness checks. | `references/python-edge-module-template.md`<br />`references/python-official-best-practices.md` |