Minor code update for easy difficulty level.

Recalculated all numbers based on a 100 Sol timeline for clarity. Extended Sol timeline so percentages will apply indefinitely, but percentages fall off starting at Sol 500. Improved descriptions. Added a new Breakthrough technology.

Minor update to new technology description.

Minor update to add challenge percentages to the game rule selection screen.

Substantial rework. Standardized the configuration choices so each option takes place over 500 Sols, with the rate of degradation changing based on the option selected (instead of the length of time). Added additional configuration levels. Added langugage about difficulty levels. Added Drone Battery Replacement technology in the Robotics tree.

Cleaned up code

Initial release