0.1.0-preview.5

The fifth preview adds two reading switches, so a chapter can be read as
running prose without verse numbers.

For reviewers, three new texts in every language: the two switches in
Settings and one sentence about them in Help, under Marks. They are listed in
docs/plans/reader-i18n/README.md.

Added

• Two reading switches in Settings: Start each verse on a new line and
  Show verse numbers. Off, a chapter reads as running prose without
  numbers, closer to how it was first written. They change only how the
  chapter looks: pressing a sentence still picks the verse it belongs to, and
  highlighting, quoting, linking and the canvas work as before. Japanese and
  Chinese run their verses together without a space; a comparison keeps its
  rows and numbers.