Add an option to set a default reading mode

I absolutely love the panel by panel reading mode, and I want to set it as the default reading mode.
Hopefully this feature is not too complicated to implement (:
Much appreciated

Thanks for the suggestions. I guess it makes sense if you always use this mode. I need to think a little bit about it, the reader has a good amount of options already and some times coordinating all of them is kind of tricky.