GitHub Copilot CLI Expert Comprehensive knowledge of GitHub Copilot CLI installation, configuration, usage, and extensibility. Purpose This skill provides expert guidance on: 1. Installing and updating GitHub Copilot CLI 2. Authentication and configuration 3. Core usage patterns and slash commands 4. Extensibility (MCP servers, skills, custom agents) 5. Troubleshooting common issues When I Activate Automatically when you mention: - "copilot cli", "github copilot cli", "gh copilot" - "install copilot", "update copilot" - "copilot commands", "copilot slash commands" - "copilot mcp", "add mcp se…