Add README Instructions for DataSQRL Claude Desktop Integration

[denisekgosnell]

Description

Add README instructions for configuring DataSQRL to work with Claude Desktop via MCP.

Requirements

The README should include:

1. Prerequisites - Docker Desktop, Claude Desktop
2. Claude Desktop Setup - How to add MCP server config to claude_desktop_config.json
3. DataSQRL Setup - Docker commands to build and run the server
4. Verification - How to confirm the MCP connection works
5. Troubleshooting - Common issues and how to access Claude Desktop logs

Keep it simple and focused on getting users up and running quickly.

[denisekgosnell]

PR: #91