Sphinxcontrib-opendataservices-jsonschema

Added

- Add `addtargets` option to `jsonschema` directive https://github.com/OpenDataServices/lib-cove-web/pull/96

Changed

- Removed Python 2 Support
- Remove use of `six` library (This was not included in `setup.py` anyway, which was a bug.)
- Switch to MyST-Parser from recommonmark https://github.com/OpenDataServices/sphinxcontrib-opendataservices-jsonschema/pull/27
- Correct the requirements https://github.com/OpenDataServices/sphinxcontrib-opendataservices-jsonschema/pull/28

First release of new forked project