docs: add initial Concord documentation page in HTML

[sajz]

Checklist

• [x] poetry run pytest passes locally with my changes
• [x] Documentation has been updated as needed
• [x] Code style checks pass
• [x] Commit messages follow the Conventional Commits guidelines

Affected Components

Documentation

Description of Changes

• Added HTML structure for the Concord project documentation page.
• Includes sections for Overview, Mission and Values, Key Features, Technical Stack, Areas for Contribution, Next Steps, and Relevant Links.
• Provides a well-formatted structure for easy navigation and readability.

Additional Notes