Note that the schema currently supports both string and object analysis in the
"analysis" field of a result.

Closes #26

There was no need to add @list, and it was causing JSON-LD to expand the
URI of 'plugins'

Closes #17

* Added debug Dockerfile/Makefile
* Validation of examples in docs

There are also some slight changes to the JSON schemas and the use of
JSON-LD.