step_func missing documentation exp_hydro

[olivierbonte]

The function step_func is not defined the tutorial on building exp hydro (https://github.com/chooron/HydroModels.jl/blob/main/docs/src/implements/build_exphydro_model_en.md), which makes running the example not feasible.

[chooron]

Hello, I apologize for not checking this issue. This step_func is a function used for smoothing the judgment process:

step_func(x) = (tanh(5.0 * x) + 1.0) * 0.5

[olivierbonte]

Thank you for the clarification! With the updated documentation from 7727d7d it is much clearer