[feat] Add Lean LSP MCP to README

[oOo0oOo]

Description

This PR adds the lean-lsp-mcp server to the list in the README.md. This MCP server allows interaction with the Lean theorem prover via the Language Server Protocol.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options

[olaservo]

Hi, could you resolve the conflicts? Thanks!

[olaservo]

Thanks for your contribution to the servers list. This has been merged in this combined PR: #2007

This is a new process we're trying out, so if you see any issues feel free to re-open the PR and tag me.