Fix incorrect coloring of in-editor documentation when theme changed

editor/editor_help.cpp

@@ -1467,6 +1467,10 @@ void EditorHelp::_notification(int p_what) {
 
 			_update_doc();
 		} break;
+		case NOTIFICATION_THEME_CHANGED: {
+
+			_class_desc_resized();
+		} break;
 		default: break;
 	}
 }