Advertise Docker Skills in llms.txt discovery links

Signed-off-by: David Karlsson <35727626+dvdksn@users.noreply.github.com>

layouts/home.llms.txt

@@ -16,6 +16,7 @@ Hub, Docker Scout, and Docker AI features.
 Use this file as a generated discovery guide for the docs site. For the complete
 page index, use [llms-full.txt](https://docs.docker.com/llms-full.txt).
 
+> Docker Skills for AI coding agents: https://docs.docker.com/ai/skills/
 > MCP endpoint for structured agent access: https://mcp-docs.docker.com/mcp
 > Bulk text corpus for offline indexing: https://docs.docker.com/llms-full.txt