Switch to separate config import

Import default config from separate path (require('tailwindcss/defaultConfig')) to allow importing the default config without importing all of Tailwind, which causes errors with Webpack due to a dynamic require.

docs/source/docs/configuration.blade.md

@@ -29,5 +29,5 @@ Please see the [installation](/docs/installation#4-process-your-css-with-tailwin
 As you can see below, the default config file is heavily documented. Read through it to get a better understanding of how each section can be customized for your project.
 
 ```js
-{!! file_get_contents(dirname(dirname(__DIR__)).'/defaultConfig.js') !!}
+{!! str_replace('// var defaultConfig', 'var defaultConfig', file_get_contents(dirname(dirname(__DIR__)).'/defaultConfig.stub.js')) !!}
 ```

docs/tailwind.js

@@ -1,4 +1,4 @@
-var config = require('../lib/index').defaultConfig()
+var config = require('../defaultConfig')()
 
 config.colors = Object.assign(config.colors, {
   'slate-darker': '#212b35',

docs/webpack.mix.js

@@ -7,7 +7,7 @@ const tailwind = require('./../lib/index.js')
 const config = require('./../defaultConfig.js')
 const fs = require('fs')
 
-fs.writeFileSync('./tailwind.json', JSON.stringify(config))
+fs.writeFileSync('./tailwind.json', JSON.stringify(config()))
 
 const env = argv.e || argv.env || 'local'
 const plugins = [