Update input.md and fix scripts (#4263)

* 统一使用es6风格的方式引入vue包

* 修正回车换行符处理，以免每次npm run dev 时，index.js都会更改

* 更新编码

build/bin/build-entry.js

@@ -3,6 +3,7 @@ var fs = require('fs');
 var render = require('json-templater/string');
 var uppercamelcase = require('uppercamelcase');
 var path = require('path');
+var endOfLine = require('os').EOL;
 
 var OUTPUT_PATH = path.join(__dirname, '../../src/index.js');
 var IMPORT_TEMPLATE = 'import {{name}} from \'../packages/{{package}}/index.js\';';
@@ -82,10 +83,10 @@ ComponentNames.forEach(name => {
 });
 
 var template = render(MAIN_TEMPLATE, {
-  include: includeComponentTemplate.join('\n'),
-  install: installTemplate.join(',\n'),
+  include: includeComponentTemplate.join(endOfLine),
+  install: installTemplate.join(',' + endOfLine),
   version: process.env.VERSION || require('../../package.json').version,
-  list: listTemplate.join(',\n')
+  list: listTemplate.join(',' + endOfLine)
 });
 
 fs.writeFileSync(OUTPUT_PATH, template);

examples/docs/en-US/input.md

 <script>
-  var Vue = require('vue');
+  import Vue from 'vue';
   Vue.component('my-item-en', {
     functional: true,
     render: function (h, ctx) {

examples/docs/zh-CN/input.md

 <script>
-  var Vue = require('vue');
+  import Vue from 'vue';
   Vue.component('my-item-zh', {
     functional: true,
     render: function (h, ctx) {