v0.18.3

• The UI uses the full window width. main was capped at 1200px and not centred, so on
  a wide screen everything hugged the left edge with an empty strip on the right — it read
  as though something was missing. The cap is gone: the views are mostly tile grids, and
  more tiles per row is exactly what they want. Explanatory paragraphs stay capped at a
  readable line length, since prose running the full width of a wide monitor is not.