sanity: move from json to yaml
changing to suport yaml rather than json and adding optional restructuredtext support
fix: parsing of yaml forematter
revert: adding json support
fixes: returning json parsing, error messages, yaml header offsets
fix: changing terminal yaml line, generalizing forematter splitting
minor: correcting example
Merge pull request #2 from tychoish/yaml-rst-support

Switching to YAML and adding support for optional restructured text parsing