docs(list-header): update angular to standalone

Author: brandyscarney

static/usage/v7/list-header/basic/angular.md

@@ -0,0 +1,12 @@
+```ts
+import { Component } from '@angular/core';
+import { IonLabel, IonListHeader } from '@ionic/angular/standalone';
+
+@Component({
+  selector: 'app-example',
+  templateUrl: 'example.component.html',
+  styleUrls: ['example.component.css'],
+  imports: [IonLabel, IonListHeader],
+})
+export class ExampleComponent {}
+```

static/usage/v7/list-header/buttons/angular.md

@@ -7,8 +7,9 @@ import react_main_tsx from './react/main_tsx.md';
 
 import vue from './vue.md';
 
-import angular_example_component_css from './angular/example_component_css.md';
 import angular_example_component_html from './angular/example_component_html.md';
+import angular_example_component_css from './angular/example_component_css.md';
+import angular_example_component_ts from './angular/example_component_ts.md';
 
 <Playground
   version="7"
@@ -23,8 +24,9 @@ import angular_example_component_html from './angular/example_component_html.md'
     vue,
     angular: {
       files: {
-        'src/app/example.component.css': angular_example_component_css,
         'src/app/example.component.html': angular_example_component_html,
+        'src/app/example.component.css': angular_example_component_css,
+        'src/app/example.component.ts': angular_example_component_ts,
       },
     },
   }}