Fixed typo in DockContainerWidget.h (#750)

Author: colebeezley

src/DockContainerWidget.h

@@ -60,7 +60,7 @@ struct AutoHideDockContainerPrivate;
 
 /**
  * Container that manages a number of dock areas with single dock widgets
- * or tabyfied dock widgets in each area.
+ * or tabified dock widgets in each area.
  * Each window that support docking has a DockContainerWidget. That means
  * the main application window and all floating windows contain a 
  * DockContainerWidget instance.