* submodule docs are now located at /api/yaml/<name>.html instead of
/api/<name>.html.
* can now simply link to symbols in other modules.
* fixed some links
* fixed quickstart example list
* added quickstart item displaying the new style api
* fixed a bug in presenter that doubled a line in literal/flow style
* NimYAML now uses the tag prefix tag:nimyaml.org,2016:
* That tag handle is shortened to !n! when presenting
* Also fixed some minor bugs dealing with tag handles