keynot 0.5.0

Added

• Press s during a show to peek at the current slide's speaker
  notes in an overlay; any key closes it.

Changed

• Code windows lost their traffic-light dots: just the rounded frame
  and the language label now.

Fixed

• An emoji shortcode at the start of a line (:crab: A Ferris Talk)
  no longer parses as definition-list syntax, which ate the colon,
  bolded the previous line as a "term", and indented the text. Known
  shortcodes at line starts are now replaced before markdown parsing;
  code fences and unknown names are untouched.