Use version-sorting for all sorting
Add a description of a version-sorting algorithm. (This algorithm does
not precisely match `strverscmp`; it's intentionally simpler in its
handling of leading zeroes, and produces a result easier for humans to
easily understand and do by hand.)
Change all references to sorting to use version-sorting.
Change all references to "ASCIIbetically" to instead say "sort
non-lowercase before lowercase".
3cc4e02519