Set changelog date for 2.0.0 release

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Release v1.0.0 — re-release of 0.15.5 as stable

update CHANGELOG

update docstring (this time for sure!)

update CHANGELOG

finalize 0.15.1

0.15.0 release: remove "coming soon" notice

remove Python 3.4 from CI as it's no longer available

Update version number

Oops.