fix(templates): reorders postcss plugins

[gkennedy87]

This The plugin order in postcss.config.js was causing UI rendering issues in mobile Safari (#10135). This pull request affects the website template and the vercel website template.

Current version:

// Website template:  /templates/website/postcss.config.js
// Vercel website template: /templates/with-vercel-website/postcss.config.js

export default {
  plugins: {
    autoprefixer: {},
    tailwindcss: {},
  },
}

PostCSS was loading Autoprefixer before Tailwind and the vendor prefixes were not properly being prepended.

Fixed version (per Tailwind docs):

export default {
  plugins: {
    tailwindcss: {}, // this is first
    autoprefixer: {}, // this is second
  },
}

[gkennedy87]

@paulpopus I see that some of the checks are failing. What needs to be fixed to pass the all green?