Docs/quickstart usage guide

[Himaan1998Y]

Summary

• add a Quick Start section with the core prepare once, layout many times mental model
• add framework integration snippets for React, Vue (Composition API), and Angular (signals)
• add an API chooser table for common starting points
• add a curated set of verified live demo links for first-time exploration

Why

Fixes #8.

The demos are compelling, but it is hard for new users to know where to start without reading source code. This keeps the change README-only and focuses on the first integration questions contributors asked for (including Angular/React/Vue usage).

Verification

• bun run check
• bun test
• trufflehog filesystem README.md --no-update (0 verified, 0 unverified)
• live URL probe for README links (all current URLs return 200)

[Himaan1998Y]

Thanks for building this. I focused this PR on issue #8 with beginner-friendly onboarding and framework integration examples (React/Vue/Angular), plus verified demo links.
Quick overlap note for maintainers: I saw #21 and intentionally kept this PR README-first and scoped to a minimal onboarding path for issue #8.

How this PR is scoped:

• no new docs file (README-only)
• short Quick Start mental model (prepare once, layout many times)
• copy-pasteable framework snippets (React/Vue/Angular)
• verified demo entry links + API chooser table

How #21 differs:

• adds a full USAGE.md deep-dive with many advanced patterns

Happy to align either way: if maintainers prefer the USAGE.md approach, I can trim this further to only the smallest unique README deltas that are still useful.