v0.5.0: Implements cal_to_jd

Fix https://github.com/roukmoute/polyfill-calendar/issues/5

v0.4.2

Cast int at each division to match C behavior

v0.4.1

Fix undefined array key error

v0.4

Fix Psalm errors

v0.3

Explicit int cast for PHP 8 compatibility

v0.2

Add easter_days() function

v0.1

Add easter_date() function