docs: update documentation on creating a custom material module

Author: ahasall

guides/getting-started.md

@@ -82,16 +82,15 @@ import {MatButtonModule, MatCheckboxModule} from '@angular/material';
 export class PizzaPartyAppModule { }
 ```
 
-Alternatively, you can create a separate NgModule that imports all of the
+Alternatively, you can create a separate NgModule that exports all of the
 Angular Material components that you will use in your application. You can then
 include this module wherever you'd like to use the components.
 
 ```ts
 import {MatButtonModule, MatCheckboxModule} from '@angular/material';
 
 @NgModule({
-  imports: [MatButtonModule, MatCheckboxModule],
-  exports: [MatButtonModule, MatCheckboxModule],
+  exports: [MatButtonModule, MatCheckboxModule]
 })
 export class MyOwnCustomMaterialModule { }
 ```