Release v0.3.3

* converters.py: xarray to data package that align indices
* customisable registry using context managers

Release v0.3.2

- Python API to convert to IAMC directly from dataframes
- Update IAMC conversion documentation

Release patch version 0.3.1

Release version 0.3

Add missing package data (template files)

Release package version 0.2

bump version

workflows: test release to PyPI

dev: fix registry patch