2.4.0

CHANGES:

Added

• Add support for external search engines (@panglesd, @EmileTrotignon, #972)
  This includes the generation of an index and the display of the results in
  the UI (HTML only).

• Display 'private' keyword for private type extensions (@gpetiot, #1019)

• Allow to omit parent type in constructor reference (@panglesd,
  @EmileTrotignon, #933)

Fixed

• Warn and exit when table(s) is not closed (@lubegasimon, #1050)
• Hint when list(s) is not closed (@lubegasimon, #1050)
• Fix crash on functors returning an alias (@Julow, #1046)
• Fix rendering of polymorphic variants (@wikku, @panglesd, #971)
• Add references to extension declarations (@gpetiot, @panglesd, #949)

Changed

• Style: Adjusted line height in the TOC to improve readability (@sorawee, #1045)
• Style: Remove font fallback to Helvetica, Arial (@Julow, #1028)
• Style: Preformatted elements fallback to UA monospace (@toastal, #967)
• Style: Sidebar is now stuck to the left of the content instead of the left of
  the viewport (@EmileTrotignon, #999)