Enhance README and initialize documentation foundation

[hckhanh]

### Summary
This pull request revises the README file for improved clarity and adds expanded API documentation for better user guidance. New sections on installation, usage examples, and Vietnamese language rules have been included. Dependencies have been updated, incorporating `vn-number` for enhanced integration.

Additionally, a new `docs` directory has been initialized, featuring a `.gitignore`, base README, and support files for documentation. Biome has been configured for linting and formatting, with a `bun.lock` file to manage dependencies.

### Changes
- Improved README with expanded content and clearer language.
- Added detailed API documentation, including installation and usage.
- Introduced `vn-number` dependency for better functionality.
- Established `docs` directory and support files for project documentation.
- Configured Biome for linting and included a `bun.lock` file.

### Checklist
- [ ] I have added necessary documentation for my changes.
- [ ] I have updated the README as needed.
- [ ] I have tested my changes and fixed any issues discovered.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (014b6b1) to head (937b31c).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff            @@
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  Coverage   100.00%   100.00%           
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  Files            6         6           
  Lines          245       245           
  Branches        82        82           
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  Hits           245       245           

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[Copilot]

Pull Request Overview

This PR adds comprehensive documentation for the vn-number library using Next.js and Fumadocs. The main purpose is to create a documentation website that provides detailed API references, usage examples, and guides for the library.

Key changes:

• Sets up a Next.js-based documentation site with Fumadocs UI framework
• Adds comprehensive MDX documentation covering API reference and getting started guides
• Updates the main README with better structure and more detailed examples

Reviewed Changes

Copilot reviewed 25 out of 29 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
mise.toml	Adds Bun 1.3.1 to the development tools configuration
docs/vercel.json	Configures Vercel deployment to use Bun 1.x
docs/package.json	Defines Next.js documentation site dependencies
docs/bun.lock	Bun lockfile for docs dependencies
docs/biome.json	Linter and formatter configuration for the docs project
docs/tsconfig.json	TypeScript configuration for the documentation site
docs/next.config.mjs	Next.js configuration with MDX support
docs/source.config.ts	Fumadocs MDX configuration for content processing
docs/postcss.config.mjs	PostCSS configuration for Tailwind CSS
docs/src/mdx-components.tsx	MDX component customization setup
docs/src/lib/source.ts	Content source adapter configuration
docs/src/lib/layout.shared.tsx	Shared layout options for documentation pages
docs/src/fonts.ts	Font configuration (JetBrains Mono)
docs/src/app/og/docs/[...slug]/route.tsx	Open Graph image generation for docs pages
docs/src/app/llms-full.txt/route.ts	LLM-friendly text export endpoint
docs/src/app/layout.tsx	Root layout with metadata and font setup
docs/src/app/global.css	Global CSS with Tailwind and Fumadocs styles
docs/src/app/docs/layout.tsx	Documentation section layout
docs/src/app/docs/[[...slug]]/page.tsx	Dynamic documentation page rendering
docs/src/app/api/search/route.ts	Search API endpoint
docs/content/docs/meta.json	Documentation navigation metadata
docs/content/docs/index.mdx	Getting started documentation
docs/content/docs/api-reference.mdx	Complete API reference documentation
docs/README.md	Documentation project README
docs/.gitignore	Gitignore for documentation project
README.md	Updated main README with improved structure and examples
pnpm-lock.yaml	Updated lockfile with removed Biome platform-specific packages and added libc metadata

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

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[Copilot]

[nitpick] Using a major version range '1.x' for bunVersion may lead to unexpected behavior when Bun releases breaking changes in minor versions. Consider pinning to a specific version or using a more restrictive range like '1.3.x' for better reproducibility.

Suggested change

	"bunVersion": "1.x"
	"bunVersion": "1.3.x"

[Copilot]

PostCSS 8.5.6 is outdated and may contain known security vulnerabilities. The latest PostCSS 8.x versions address several security issues. Consider updating to the latest 8.x version (8.4.x series).

Suggested change

	"postcss": "8.5.6",
	"postcss": "8.4.38",

[codspeed-hq]

CodSpeed Performance Report

Merging #46 will not alter performance

_{Comparing docs (937b31c) with main (014b6b1)}

Summary

✅ 64 untouched

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud