Bump version mentioned in the README

Author: joedursun

README.md

@@ -50,7 +50,7 @@ path to `uvx`.
 
 ```bash
 # Claude CLI
-claude mcp add polygon -e POLYGON_API_KEY=your_api_key_here -- uvx --from git+https://github.com/polygon-io/mcp_polygon@v0.1.0 mcp_polygon
+claude mcp add polygon -e POLYGON_API_KEY=your_api_key_here -- uvx --from git+https://github.com/polygon-io/mcp_polygon@v0.2.1 mcp_polygon
 ```
 
 This command will install the MCP server in your current project.