Clarify built-in MCP servers in Copilot CLI reference#43372

aosama wants to merge 1 commit intogithub:maingithub/docs:mainfrom

aosama:issue-43371-copilot-cli-built-in-mcp-docsaosama/docs:issue-43371-copilot-cli-built-in-mcp-docsCopy head branch name to clipboard