docs(mcp-server): add Smithery connection guide

Author: masnwilliams

reference/mcp-server.mdx

@@ -145,6 +145,20 @@ Click [here](goose://extension?cmd=npx&arg=-y&arg=mcp-remote&arg=https%3A%2F%2Fm
 }
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+### Smithery
+
+You can connect directly to `https://mcp.onkernel.com/mcp`, or use Smithery as a proxy if you prefer by using its provided URL.
+
+- Use Smithery URL in any MCP client:
+  1. Open [Smithery: Kernel](https://smithery.ai/server/kernel).
+  2. Click "Get connection URL" and copy `https://server.smithery.ai/kernel/mcp`.
+  3. Paste it into your MCP client's "Add server" flow.
+
+- Use Kernel in Smithery's Playground MCP client:
+  1. Open [Smithery Playground](https://smithery.ai/playground).
+  2. Click "Add servers", search for "Kernel", and add it.
+  3. Sign in and authorize Kernel when prompted.
+
 ### Others
 
 Many other MCP-capable tools accept: