v2.27.1

New

• Every built-in table style is named. TableStyle exposed five of
  Excel's sixty, so the other fifty-five had to be written as raw strings.
  All of them are now constants: light1 to light21, medium1 to
  medium28, dark1 to dark11, plus none. A style is only a name in the
  file, so an arbitrary string still works and always did; this is for
  checking the name at compile time rather than guessing it.

Notes

The five names that existed before keep the same values, so nothing changes
for code already using them.