Updated usage, configuration, and licence sections in README.
Adding source code annotations for global plugin properties.
Added annotations for plugin methods.
Added additional placeholder and missing annotations.
Added example snippets to annotations.
Added method names to annotations.
Refactored complex objects in annotations using @typedef.
Fixed bug with incorrect reference to sunset_color property during sunset.
Refactored day, night, sunrise, sunset colors into sky_color property.
Added annotations for sky_color property.
Added file description to atmosphere-debug.js. Renamed custom typedefs in atmosphere.js annotations due to ambiguity.