pub const CELL_WIDTH_CLASSES: &[&str];Expand description
Every class saying how wide a cell of a column asks to be, including the fill a column that makes no claim lands on.
See ROW_PART_CLASSES for why it is written out. Only two of the three
carry a rule, a fill is what a cell does when the sheet says nothing,
which is exactly why the list is here rather than being read off the
generated CSS: cell-fill reached every table in the tree and the
vocabulary named it nowhere.