docs: add spec-kit-copilot to community friends

Assisted-by: GitHub Copilot (model: Claude Opus 4.8, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: c4ad8a5e-3ddb-44b2-b8ec-4f438c636b61

Author: mnriem

docs/community/friends.md

@@ -16,3 +16,5 @@ Community projects that extend, visualize, or build on Spec Kit:
 - **[cc-spec-kit](https://github.com/speckit-community/cc-spec-kit)** — Community-maintained plugin for Claude Code and GitHub Copilot CLI that installs Spec Kit skills via the plugin marketplace.
 
 - **[spectatui](https://github.com/tinesoft/spectatui)** — A terminal UI (TUI) dashboard for Spec Kit that lets you track features, manage specifications, integrations, presets, workflows, and extensions, and monitor AI agent workflows. Attach to existing AI sessions or launch new ones from your terminal. Keyboard and mouse support. Light/dark theme support. Customizable and performance-oriented. Requires the `specify` CLI in your PATH.
+
+- **[spec-kit-copilot](https://github.com/github/spec-kit-copilot)** — A GitHub Copilot **skills plugin** that exposes the Spec Kit `specify` CLI to the Copilot agent in both the Copilot CLI and the GitHub Copilot app. It provides a focused skill per `specify` command group — setup, init, check, extensions, presets, bundles, workflows, workflow steps, and self-upgrade — so you can navigate and drive the entire Spec Kit ecosystem through natural language, letting Copilot decide when and how to run the right `specify` commands on your behalf.