Added class-level javadocs for Animal.
Added class-level javadocs for AnimalFactory.
Added class-level javadocs for Antelope.
Added class-level javadocs for Bear.
Added class-level javadocs for InvalidArgumentException.
Added class-level javadocs for FlightMoveStrategy.
Added class-level javadocs for MovementStrategy.
Added class-level javadocs for FightMoveStrategy.
Added class-level javadocs for RandomMoveStrategy.