Add Units of measurement to the input variables

[AlessandroAmadoriTNO]

Hello!

When using the module to run some simulations using input parameters provided by third parties, I realised that the documentation does not provide explicit units of measurement.

I think it would improve usability to explicit them, to make sure that there are no ambiguities in the input parameters and if the parameters are indeed the same then the variables can be converted (ex: seconds ↔ nanoseconds).