docs: drop the stale agent rules card from the MCP next steps

Author: ericallam

docs/mcp-introduction.mdx

@@ -382,7 +382,4 @@ Once installed, you can start using the MCP server by asking your AI assistant q
   <Card title="Skills" icon="wand-magic-sparkles" href="/skills">
     Portable instruction sets that teach AI assistants Trigger.dev patterns.
   </Card>
-  <Card title="Agent Rules" icon="scroll" href="/mcp-agent-rules">
-    Install comprehensive rule sets directly into your AI client.
-  </Card>
 </CardGroup>