* Renamed some symbols for consistency, fixes#6:
- yamlStartSequence -> yamlStartSeq
- yamlEndSequence -> yamlEndSeq
- yamlStartDocument -> yamlStartDoc
- yamlEndDocument -> yamlEndDoc
- yTagMap -> yTagMapping
* Improved code formatting at some places
* Fixed code documentation at some places
* Added generic objects to TODO list
* Removed obsolete parsing tests, these are superseeded
by yaml-dev-kit test suite integration
* use `[]=` instead of add() to add JSON nodes to an object.
add() seems to have problems with expanding.
* renamed bench/json.nim to bench/jsonBench.nim to avoid confusion
with Nim's stdlib json.nim
* Added serialization.txt to doc
* Fixed rendering problem in api.txt
* Use explicit tag when ref type renders to a scalar that can be
parsed to !!null
* Added test cases for this ref type fix
* Some typo fixes in code
* nim documentation now generates API doc with source links
* presenter now uses "" if a string starts with @ or `
* Removed some outdated stuff