FEATURE : Add basic routing and separate 404 page (React Router)

[kunal-bunkar]

Feature and its Use Cases

Feature Add minimal client-side routing to OrgExplorer using react-router-dom and extract the 404 UI into a dedicated component file.

What changes
-Wrap the app with BrowserRouter in src/main.tsx
-Define routes in src/App.tsx:
-/ renders the existing home UI (currently “Hello, OrgExplorer!”)
-renders a 404 page component

Use cases
-Users get a proper 404 fallback for invalid URLs
-Sets up a scalable routing foundation for future features (org details/repo views) while keeping current UI intact
-Improves navigation structure without changing app behavior on /

Acceptance criteria
-Visiting / shows the home UI
-Visiting any unknown route shows the 404 page with a link back to /
-npm run lint passes

Additional Context

Additional Context
-Dependency: react-router-dom
-New file added: src/NotFoundPage.tsx
-Only minimal routing introduced (no extra pages/routes beyond home + 404)

Code of Conduct

• I have joined the Discord server and will post updates there
• I have searched existing issues to avoid duplicates