[docs] Binary doesn't show up for searches of "serialization" on hackage

I don't know which spelling is more common, but it might be worth using the 'z' spelling in the description somewhere as well, since only cereal shows up if you search for serialization.

Maybe switch to 'z' entirely, or get cereal to switch to 's'?

Maybe this should be a hackage issue? I'm not sure, but it's sad to imagine which library to use is being decided by spelling and I thought I should note this somewhere.