$ ng add @angular/material // To install Angular Material

// Using a pre-built theme : deeppurple-amber.css, indigo-pink.css, pink-bluegrey.css, purple-green.css	
// 

// create a xxxModule with routing in the "shared folder" and register it with the root AppModule.
ng g m shared/xxx --module=app --flat 
// ===>
$ ng g m shared/shared --module=app --flat  // CommonModule, NgModule, ... 
$ ng g m shared/material --module=app --flat 
 
// dashboard
$ ng g m dashboard/dashboard --module=app --flat
$ ng g c dashboard/dashboard

// dashboard
$ ng g m about/about --module=app --flat
$ ng g c about/about

// error
$ ng g m error/error --module=app --flat
$ ng g c error/page-not-found

// Then 
$ ng g c shared/layout/footer/footer --module=shared --flat
$ ng g c shared/layout/sidenav/sidenav --module=shared --flat 
$ ng g c shared/layout/topbar/topbar --module=shared --flat