记忆折叠状态并与导图一致 Remember collapes status in accordance with mindmap

[ycbrd]

#382

[deevilboy]

Please add this feature -- it's the only feature I need to make a subscription worthwhile. Else, my mindmaps are unusable as they are too large for me to view all the lines at once. I have to spend a lot of time collapsing everything back to a "small enough" view. I have to do this EVERY SINGLE TIME I open one of your mind maps.

Thanks for building the tool so far.