v0.16

• Improved BIDS compliance: made session and run entities optional; added acq entity, improved argument parsing in CLI, now using derivatives directory for 'derived' types such as masks, segmentations and fieldmaps; also used suffixes correctly including _Chimap, _fieldmap, _dseg and _mask, including the _desc- entities when multiple derivatives are generated that would otherwise clash.
• Removed docs since they were difficult to maintain with minimal effort - the docstrings on the functions are good enough for now and the examples should make it clear how to use the software