Enable retaining floats in function list_to_dict in log posterior probability function

[twallema]

• I have checked to ensure there aren't other open Pull Requests for the same update/change
• I have updated the documentation accordingly.

Describe your fixes/additions/changes

Calibrated parameters

In #84 the default behavior of list_to_dict when encountering a float was changed to retain_floats=False bc this made more sense in the context of simulations. However, list_to_dict is also used in the computation of the log posterior probability and there it makes more sense to have retain_floats = True.

This PR changes the behavior of the list_to_dict called in the log posterior probability function to retain_floats=True. The default setting however remains retain_floats=False.