Bounty: Add Documentation for React.js Frontend

[samsamtrum]

Summary

Adds a project-specific README for Kleo Connect, replacing the Vite starter template documentation with practical frontend documentation for contributors and reviewers.

What changed

• Added a clear project overview and feature summary
• Documented the React/Vite/TypeScript/Tailwind tech stack
• Added repository structure notes for src/common, src/pages, assets, routing, hooks, and dashboard modules
• Added setup, environment variable, script, testing, build, deployment, contribution, and troubleshooting sections
• Included security notes for Vite-exposed environment variables

Validation

• npm run test -- --run passed
• npm run build passed
• git diff --check passed

Note: a plain npm install initially failed under the current local Node environment because node-datachannel could not build its native prebuild step. Re-running install with npm install --ignore-scripts completed and allowed the docs-only validation commands above to run successfully.

Closes #56