private void VisualEditor_TextChanged(object sender, EventArgs e)
 {
     OnHtmlChanged?.Invoke(sender, null);
 }
 private void CodeEditor_TextChanged(object sender, TextChangedEventArgs e)
 {
     OnHtmlChanged?.Invoke(sender, e);
 }
 private void Document_Click(object sender, System.Windows.Forms.HtmlElementEventArgs e)
 {
     OnHtmlChanged?.Invoke(sender, null);
 }