Add clarification to Cross-staff notation documentation that it will not change a note's home stave

The Cross-staff notation page claims ctrl+shift+up/down will "move the voice up or down to the other staff"

However this is only visually, if you then click on one of those notes you will find it's 'home' (for lack of a better word) stave hasn't changed. This makes shift-click selecting notes for copy and paste and other functions go horribly wrong

Some warning about this functionality would be appreciated. The workaround seems to be to copy and paste notes from one stave to another, which may require the selection filter to be used to not select multiple voices when doing so