Add delete text action

src/common/array.ts

@@ -1,3 +1,10 @@
 export function insert<T>(arr: T[], index: number, slice: T[]): T[] {
     return [...arr.slice(0, index), ...slice, ...arr.slice(index)];
 }
+
+export function remove<T>(arr: T[], idx: number, count: number = 1): T[] {
+    return [
+        ...arr.slice(0, idx),
+        ...arr.slice(idx + count)
+    ];
+}

src/components/Fluent.tsx

@@ -8,7 +8,7 @@ import { SelectionService } from '../services/selection.service';
 export class Fluent extends Component<any, any> {
     private editorStateService = new IEditorStateService();
     private selectionService = new SelectionService();
-    
+
     public render() {
         return (
             <div className={styles.Fluent}>