Gets a command to substitute a footer sub-document with a header sub-document of the same page as an active sub-document.
readonly goToHeader: GoToHeaderCommand
A GoToHeaderCommand object that provides methods for executing the command and checking its state.
You can invoke this command by calling the execute method.
The execute method checks the command state (obtained using the getState method) before executing, and decides whether the action can be performed. The execute and getState methods are members of the GoToHeaderCommand class.
If the header sub-document does not exist for the current page, the command creates it.
The active sub-document is available via the RichEditDocument.activeSubDocument property.