[PULL REQUEST] Minor update in the deposition menu in input.geos.

[joeylamcy]

I would like to suggest changing the following in the deposition menu in input.geos:

 Turn on Dry Deposition? : F
 Turn on Wet Deposition? : F
 Turn on CO2 Effect?     : F
-CO2 level               : 600.0
-Reference CO2 level     : 380.0
+ => CO2 level           : 600.0
+ => Reference CO2 level : 380.0
 Diag alt above sfc [m]  : 10

These lines are about scaling the stomatal resistance with a specified CO2 concentration (#41). Introducing such changes can clarify what the inputs are for and would avoid confusion in the future as I'm preparing my PR #629, which would also take a CO2 concentration as input.