Move docs to a separate repo to decrease main repo size

docs/src/.vuepress/enhanceApp.js

@@ -1,14 +0,0 @@
-/**
- * Client app enhancement file.
- *
- * https://v1.vuepress.vuejs.org/guide/basic-config.html#app-level-enhancements
- */
-
-export default ({
-  Vue, // the version of Vue being used in the VuePress app
-  options, // the options for the root Vue instance
-  router, // the router instance for the app
-  siteData // site metadata
-}) => {
-  // ...apply enhancements for the site.
-}