Add setup scripts for Windows and macOS/Linux

- install.bat and install.sh configure MCP for any AI tool
- Searches upward for .uproject to detect project context
- Detects engine folder for global-only scope
- Supports project scope (config in project root) and global scope
- Merges into existing config files without overwriting
- Checks if unrealmcp already configured before adding
- Supports all 8 AI tools: Claude Code, Cursor, VS Code,
  Windsurf, Gemini CLI, JetBrains, Zed, Amazon Q
- Each tool uses its correct config format and file location

Author: aadeshrao123