v0.0.6

Summary:
Added some minor improvements to functionality and to the documentation.

Itemized Changes:

• feat: make Timescale and Calendar objects subscriptable (#93)
• feat: split is_leap from calendar_days function (#99)
• docs: update README.rst (#101)
• docs: add CITATION.cff (#101)
• docs: use sphinxcontrib-bibtex to build bibliography (#112)
• ci: add windows builds (#112)

Full Changelog: 0.0.5...0.0.6