feat: add support for searching within a channel (#262)

* feat(Channel): add support for searching

* dev: add channel search test

* chore: update docs

src/parser/classes/ExpandableTab.ts

@@ -15,7 +15,7 @@ class ExpandableTab extends YTNode {
     this.title = data.title;
     this.endpoint = new NavigationEndpoint(data.endpoint);
     this.selected = data.selected; // If this.selected then we may have content else we do not
-    this.content = data.content ? Parser.parse(data.content) : null;
+    this.content = data.content ? Parser.parseItem(data.content) : null;
   }
 }