General code clean-up and documentation improvements beyond v1.0.0.
Added gs_limit_flag. The gs_limit_flag option in the .ini controls the growing season start day controls. True (default) run the model as is with a +/-40 day limit from the long term growing season average. False option applies no limits to the growing season start day and allows it to extend freely with T30.
Added additional turfgrass Kc curves (ETo) utilized during the 2020 USBR turfgrass demands analysis.
Corrected issue with CO2 adjustment double applying correction if season extends beyond Kc curve.