Add Tailwind CSS v4 + Vite installation instructions

[garrettsiegel]

Adds comprehensive instructions for installing and configuring Tailwind CSS v4+ with Vite projects.

What this covers

• Step-by-step installation using @tailwindcss/vite plugin
• Key v4 changes (no PostCSS, no tailwind.config.js)
• CSS-first configuration with @theme, @utility, and @variant
• Common mistakes to avoid (old directives, unnecessary config files)
• Migration guide from Tailwind v3
• Troubleshooting section

Why this is needed

Tailwind v4 has a fundamentally different setup than v3, and many developers (and AI assistants) still default to the old PostCSS-based approach. This fills a gap since the existing nextjs-tailwind.instructions.md is Next.js-specific.

[Copilot]

Pull request overview

This PR adds comprehensive installation and configuration instructions for Tailwind CSS v4+ with Vite projects, addressing the fundamental changes in v4's setup approach compared to v3.

Changes:

• New instruction file for Tailwind CSS v4 + Vite setup with CSS-first configuration
• Updated README to include the new Tailwind v4 + Vite instructions
• Enhanced VS Code settings with file exclusion patterns

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
instructions/tailwind-v4-vite.instructions.md	Comprehensive guide for Tailwind v4 installation covering setup steps, CSS-first configuration, migration from v3, and troubleshooting
docs/README.instructions.md	Added table entry with installation badges for the new Tailwind v4 + Vite instructions
.vscode/settings.json	Added file exclusion patterns for common system files

[Copilot]

The applyTo glob pattern includes all TypeScript and JavaScript files in the project, which may be too broad for Tailwind-specific instructions. Consider limiting this to configuration files and CSS files only (e.g., 'vite.config.{ts,js}, src/**/*.css') to avoid applying these instructions to unrelated code.

Suggested change

	applyTo: 'vite.config.ts, vite.config.js, **/*.css, **/*.tsx, **/*.ts, **/*.jsx, **/*.js'
	applyTo: 'vite.config.ts, vite.config.js, src/**/*.css'

[Copilot]

The addition of files.exclude settings and an empty hide-files.files array appears unrelated to Tailwind CSS v4 instructions. These VS Code workspace settings should either be removed from this PR or explained in the PR description as they don't support the stated purpose of adding Tailwind documentation.

Suggested change

	},
	"hide-files.files": []
	}