Update docstring for Point

[canyon289]

Docstring is missing default arguments and is missing a parameter entirely

https://github.com/pymc-devs/pymc/blob/v4-archived/pymc3/model.py#L1752

[tblazina]

I would take this one, if its not being worked on.

[mjhajharia]

@canyon289 can you provide the updated link to the source code for this issue?

[canyon289]

Done

[OriolAbril]

Closing this as it is contained in #5459 and having it open here as a separate issue will be confusing