Make role name in seeder match rest of example

Author: drbyte

docs/basic-usage/new-app.md

@@ -86,7 +86,7 @@ class PermissionsDemoSeeder extends Seeder
         $role2->givePermissionTo('publish articles');
         $role2->givePermissionTo('unpublish articles');
 
-        $role3 = Role::create(['name' => 'super-admin']);
+        $role3 = Role::create(['name' => 'Super-Admin']);
         // gets all permissions via Gate::before rule; see AuthServiceProvider
 
         // create demo users