Add support for hard tabs

* Add a `hard_tabs` setting that causes indentation to be performed
  using a tab instead of multiple spaces.
* Change Buffer's indentation-related APIs to return an `IndentSize`
  struct with a length and a kind, instead of just a single u32.
* Use hard tabs by default in Go.
f62fd3cdddMax Brunsfeld committed on 6/9/2022, 1:30:10 AMparent129fc51
8 files changedLine totals unavailable