Prevent resizing without explicitly setting minSize and maxSize

[DoubleDebug]

Hello and thanks for implementing this awesome React library!

I see that in your FAQ (linked below), you answered a question regarding the prevention of resizing: https://github.com/johnwalley/allotment#how-do-i-prevent-a-pane-from-being-resized

However, in order to do this, you would need to know exactly how wide/tall your panes are. In my opinion, there should be a boolean prop called resizable that gives more flexibility to the user.

<Allotment resizable={false}>
     <div>block 1</div>
     <div>block 2</div>
</Allotment>

Would you consider implementing this into the library? It would be much appreciated. Thanks in advance!