Angular集成font-awesome

# 集成font-awesome

```
npm i font-awesome --save
```

```
yarn add font-awesome --save
```

然后在`angular.json`的`build`和`test`对象的`styles`里添加上
```
"styles": [
  "node_modules/font-awesome/css/font-awesome.min.css",
  "src/styles.scss"
],
```
