docs(shell-docs): remove skills table, replace with prose + link

The table was incomplete (6 skills listed, 12 actually install) and has
no CI check to keep it in sync. Replace with a one-line prose summary
and a link to the canonical skills/ directory on GitHub, which is always
accurate.

Author: onsclom

showcase/shell-docs/src/content/docs/build-with-agents.mdx

@@ -26,16 +26,7 @@ Skills are folders of instructions, references, and scripts that coding agents c
 
     This pulls the latest skills directly from the CopilotKit repository and installs them into your tool's skills directory (e.g. `~/.claude/skills/` for Claude Code). The CopilotKit MCP server is also auto-wired so your agent has live documentation access.
 
-    **Skills installed:**
-
-    | Skill | Purpose |
-    |-------|---------|
-    | `copilotkit-setup` | Add CopilotKit to a project from scratch |
-    | `copilotkit-develop` | Build AI features using CopilotKit hooks and components |
-    | `copilotkit-integrations` | Connect LangGraph, CrewAI, Mastra, PydanticAI, and 10+ frameworks |
-    | `copilotkit-debug` | Diagnose streaming, agent, and runtime issues |
-    | `copilotkit-upgrade` | Migrate between CopilotKit versions |
-    | `copilotkit-contribute` | Contribute to the CopilotKit open-source repository |
+    Skills cover project setup, building AI features, connecting agent frameworks, debugging, and version upgrades. The full list is in the [CopilotKit skills directory](https://github.com/CopilotKit/CopilotKit/tree/main/skills).
 
   </Step>
   <Step>