docs(readme): add GitHub MCP Registry badge to README

Author: ihor-sokoliuk

README.md

@@ -12,6 +12,7 @@
 [![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/ihor-sokoliuk/mcp-searxng/badge)](https://scorecard.dev/viewer/?uri=github.com/ihor-sokoliuk/mcp-searxng)
 [![OpenSSF Best Practices](https://www.bestpractices.dev/projects/13143/badge)](https://www.bestpractices.dev/projects/13143)
 [![mcp-searxng MCP server](https://glama.ai/mcp/servers/ihor-sokoliuk/mcp-searxng/badges/score.svg)](https://glama.ai/mcp/servers/ihor-sokoliuk/mcp-searxng)
+[![GitHub MCP Registry](https://img.shields.io/badge/GitHub_MCP_Registry-listed-2da44e?style=flat-square&logo=github&logoColor=white)](https://github.com/mcp/ihor-sokoliuk/mcp-searxng)
 
 An [MCP server](https://modelcontextprotocol.io/introduction) that integrates the [SearXNG](https://docs.searxng.org) API, giving AI assistants web search capabilities.