How to properly include css/js in an Angular2+ distribution : I'm trying to implement an Admin Template I used in classic my classic php application in a new Angular5 project.

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="utf-8">
        <link rel="icon" type="image/png" sizes="16x16" href="/plugins/images/favicon.png">
        <title>Ample Admin Template - The Ultimate Multipurpose admin template</title>
        <link href="/bootstrap/dist/css/bootstrap.min.css" rel="stylesheet">
        <link href="/plugins/bower_components/sidebar-nav/dist/sidebar-nav.min.css" rel="stylesheet">
        <link href="/css/animate.css" rel="stylesheet">
        <link href="/css/style.css" rel="stylesheet">
        <link href="/css/colors/blue-dark.css" id="theme" rel="stylesheet">      
    </head>
    <body>
      <app-root></app-root>
    </body>
    </html>

The application is properly rendered by now I have some questions:

 1. How can I include these css/js package (and all the dependencies) in an Angular distribution? 
 2. What is the properly way to includes external css/libraries in Angular2+ ?

Thanks to support