jumpToWidgetIndex method
Scrolls the markdown content to the heading at the specified widget index.
The widgetIndex corresponds to the index in the MarkdownGenerator's widget tree.
This triggers the _jumpToWidgetIndexCallback if it has been set.
Implementation
void jumpToWidgetIndex(int widgetIndex) {
if (_isDisposed) return;
_jumpToWidgetIndexCallback?.call(widgetIndex);
}