chore: add Smithery CLI installation instructions and badge (#12)

README.md

@@ -1,5 +1,7 @@
 # mcp-proxy
 
+[![smithery badge](https://smithery.ai/badge/mcp-proxy)](https://smithery.ai/server/mcp-proxy)
+
 - [mcp-proxy](#mcp-proxy)
   - [About](#about)
   - [1. stdio to SSE](#1-stdio-to-sse)
@@ -124,6 +126,14 @@ This will start an MCP server that can be connected to at `http://127.0.0.1:8080
 
 ## Installation
 
+### Installing via Smithery
+
+To install MCP Proxy for Claude Desktop automatically via [Smithery](https://smithery.ai/server/mcp-proxy):
+
+```bash
+npx -y @smithery/cli install mcp-proxy --client claude
+```
+
 The stable version of the package is available on the PyPI repository. You can install it using the following command:
 
 ```bash