initial vitepress redistributable theme + asset syncing configuration

[josbeir]

This refactors the skeleton so it can be used as npm package greatly simplifying its distribution.

Using in a docs project

1. Install

npm install @cakephp/docs-skeleton vitepress

2. Scaffold boilerplate

npx cakedocs init

This creates two files:

File	Purpose
.vitepress/config.js	Extends the skeleton's base config
.vitepress/theme/index.js	Re-exports the CakePHP theme

3. Configure

Edit .vitepress/config.js — your overrides are merged with the base config via VitePress extends:

import baseConfig from '@cakephp/docs-skeleton/config'

export default {
  extends: baseConfig,
  base: '/5.x/',
  themeConfig: {
    sidebar: [],
    nav: [],
    socialLinks: [
      { icon: 'github', link: 'https://github.com/cakephp/cakephp' },
    ],
  },
  substitutions: {
    '|phpversion|': { value: '8.4', format: 'bold' },
    '|minphpversion|': { value: '8.1', format: 'italic' },
  },
}

4. Add scripts to package.json

{
  "scripts": {
    "docs:dev":     "vitepress dev",
    "docs:build":   "vitepress build",
    "docs:preview": "vitepress preview"
  }
}

5. Run

npm run docs:dev