0.28.0: Ball of Twine

Breaking

• Replace many of the public extensions on String, and its internal
  caching mechanism CacheContainer, with a new StringView type.
  Paul Taykalo

Enhancements

• Allow inline html tags in ObjC doc comments.
  Chris Williams
  #409
  realm/jazzy#976

• Support code formatting in ObjC doc comments with @c, @code and
  @endcode.
  Bryce Pauken
  #631

Bug Fixes

• Fix crash when SourceKit returns out of bounds string byte offsets.
  JP Simard