Bounty: Add Documentation for React.js Frontend.

[JustABiologist]

Summary

• Replaced the starter-template README with project-specific Kleo Connect documentation.
• Added setup, environment variable, project structure, key module, build/test, deployment, and contribution guidance.

Verification

• npm install --ignore-scripts
• npm run build
• npm run test -- --run

Fixes #56

Bounty note: if this PR is accepted for the listed USD bounty, PayPal payout can be sent to stab.me.papi@gmail.com.

[JustABiologist]

Adding a concise bounty-requirements mapping for review:

• Project overview and stack: covered in the README introduction and technology stack sections.
• Local setup: covered with clone, install, environment variables, and dev server steps.
• Project structure: covered with the main directories and their responsibilities.
• Build, test, and deployment: covered with the existing scripts and deployment notes.
• Contributing guidance: covered with the contribution workflow and PR expectations.

This PR was opened before the later competing documentation PRs I can see on the bounty issue, and it stays scoped to the requested README documentation work.