Update .gitignore to exclude site directory for documentation builds

[adityakedawat]

Description

Brief description of what this PR accomplishes.

Type of Change

• 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 not work as expected)
• Documentation update

Testing

• Unit tests pass
• Integration tests pass
• Manual testing completed
• Documentation updated

Checklist

• Code follows the style guidelines
• Self-review of code completed
• Code is commented, particularly in hard-to-understand areas
• Corresponding changes to documentation made
• Changes generate no new warnings
• Tests added that prove fix is effective or feature works
• New and existing unit tests pass locally
• AI assistance (e.g., Cursor, ChatGPT, Claude) was used in making these changes (please specify tools in the PR description)

Additional Context

• Link to related issues: Fixes #123
• Screenshots (if UI changes)
• Performance impact analysis
• Breaking changes explanation