Updated docstring for Potential function

[Dhruvanshu-Joshi]

What is this PR about?
This PR is a continuation of the PR 6489 in order to solve the merge conflicts.
In this PR , I have provided a solution to close the issue 6399.
The docstring for the Potential function is rather limited. I have made efforts to include some code examples to better understand this. I also focused on the nature of the arguments that are passed to this function and have included an example for the same.

Checklist

• Explain important implementation details 👆
• Make sure that the pre-commit linting/style checks pass.
• Link relevant issues (preferably in nice commit messages)
• Are the changes covered by tests and docstrings?
• Fill out the short summary sections 👇

Documentation

• Add code example and a short explanation of the code example to Potential docstrings.
• In the first example, we define a constraint such that the probability density that the model produces takes into consideration that x must be greater than or equal to 0.
• In the second example, we emphasis on the usage of soft constraints.
• The third example focuses on how the Potential function is used to obtain an arbitrary prior.
• In the final example, the soft_sum_constraint potential encourages x and y to have a small sum, effectively adding a soft constraint on the relationship between the two variables.

[codecov]

Codecov Report

Merging #6559 (2e2dcf3) into main (2f945bb) will not change coverage.
The diff coverage is n/a.

Additional details and impacted files

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  Coverage   92.01%   92.01%           
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  Files          91       91           
  Lines       15114    15114           
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  Hits        13907    13907           
  Misses       1207     1207           

Impacted Files	Coverage Δ
pymc/model.py	89.52% <ø> (ø)

[michaelosthege]

The explanations are good!

I just nitpicked about some small code/docstring style things. You can add line breaks - at least to the level of the "1 sentence per line" rule of thumb.

[Dhruvanshu-Joshi]

Hey @michaelosthege . Thanks for the review. I have included all the suggestions in the new commit.

[chriswmann]

Bad timing since this was just merged but I think there are a couple of typos in the merged commit. E.g. line 2080 says "We pass -pm.math.log(pm.math.switch(constraint, 1, 0)) as second argument" but then in the code example on line 2089, the actual argument is pm.math.log(pm.math.switch(constraint, 1, 0.0)) (i.e. the argument is not negated). Same again for the soft constraint on lines 2091 and 2103. I'm happy to raise an issue and submit a PR if it is agreed these are corrections that should be made.

[ricardoV94]

@chriswmann thanks that would be appreciated