Revert "feat: expose config.styl variables to style.styl (#727)"

This reverts commit 0bc2b51.

Author: ulivz

docs/default-theme-config/README.md

@@ -476,7 +476,6 @@ $textColor = red
 
 ``` stylus
 // .vuepress/style.styl, your extra styles.
-// variables from config.styl can be used here
 #my-style {}
 ```
 

lib/prepare/index.js

@@ -28,10 +28,9 @@ module.exports = async function prepare (sourceDir) {
   const hasUserOverride = fs.existsSync(overridePath)
   await writeTemp('override.styl', hasUserOverride ? `@import(${JSON.stringify(overridePath)})` : ``)
 
-  const configPath = require.resolve('../default-theme/styles/config.styl')
   const stylePath = path.resolve(sourceDir, '.vuepress/style.styl').replace(/[\\]+/g, '/')
   const hasUserStyle = fs.existsSync(stylePath)
-  await writeTemp('style.styl', hasUserStyle ? `@import(${JSON.stringify(configPath)})\n@import(${JSON.stringify(stylePath)})` : ``)
+  await writeTemp('style.styl', hasUserStyle ? `@import(${JSON.stringify(stylePath)})` : ``)
 
   // Temporary tip, will be removed at next release.
   if (hasUserOverride && !hasUserStyle) {