1.下载 HTML Snippets插件
2.打开setting.json文件，在里面添加如下代码：
"emmet.triggerExpansionOnTab": true,
"emmet.includeLanguages": {
"vue-html": "html",
"vue": "html"
},
"files.associations": {
// extension name : html
"*.ejs": "html",
"*.js": "html"
}