v0.4.0

Added

• splitText takes an array, or any iterable, of targets and returns one TextSplit per
  target. Every target is planned before any is written, so a page of blocks costs the one
  layout a single block does, where a loop of single splits forced one per block: a word or
  character split of an article takes about a third less time, most of all in Safari. The
  hyphen a broken word is restated with is now measured once every cut is made, for the same
  reason, in a single split as well.