feat: extract channel error alert

src/parser/classes/Alert.ts

@@ -0,0 +1,17 @@
+import Text from './misc/Text';
+import { YTNode } from '../helpers';
+
+class Alert extends YTNode {
+  static type = 'Alert';
+
+  text: Text;
+  alert_type: string;
+
+  constructor(data: any) {
+    super();
+    this.text = new Text(data.text);
+    this.alert_type = data.type;
+  }
+}
+
+export default Alert;