fix-wrong-solar-midnight (#53)

Co-authored-by: Nicolas Mariniello <[email protected]>

Immutability (#50)

Sun is now a struct: users can no longer use Sun as a reference type. However, immutability is not enforced and functions like setDate and setLocation are now defined as mutating.
Sun initializer now accepts a Date parameter (defaults to Date()).
Sun now conforms to Identifiable, Equatable, Hashable, and Sendable protocols.
Utilities such as Angle, DMS, EclipticCoordinates, EquatorialCoordinates, HMS, and HorizonCoordinates now conform to Equatable, Hashable, Sendable, and Codable protocols.

Update README.md (#47)

Better handling of circumpolar always light conditions (#42)

Dusk and dawn were inverted (#41)

Night goes from sunset to sunrise (#38)

Fixed "down" typos (#37)

Changed names (#36)

Removed 'UseSameTimeZone' dependency (#32)

Added Blue Hour (#29)