DOCS: Fix inconsistencies in existing parameter docstrings

[asoplata]

This issue consists of three efforts:

1. There are some cases where the order or presence of parameters in the docstring is inconsistent with the order of parameters in the function itself, such as https://github.com/jonescompneurolab/hnn-core/blob/master/hnn_core/viz.py#L81-L121 . All docstrings should be updated to be accurate with respect to the argument order in every function.
2. For parameters which have a default value, but their default is different than None, these optional parameters should have , default=<value> added to the end of the parameter's first line in the docstring. As an example, this

    color : tuple of float | str
        RGBA value to use for plotting. By default, 'k' (black)

should become

    color : tuple of float | str, default='k'
        RGBA value to use for plotting. By default, 'k' (black)

since this implies both that the parameter is optional, and that it has a specific default value. This is in agreement with https://numpydoc.readthedocs.io/en/latest/format.html#parameters .

3. For parameters whose default value is None, these parameters should have , optional added to the end of the parameter's first line in the docstring, in a similar manner to above.

Note that any amount of work for this is appreciated! Contributors should not feel like they have to fix every single instance of this issue before making a PR and contributing changes.

[dikshant182004]

i have updated some of the funtions docstring if that looks good we can scale it up throughout the code base .

[gearupsmile]

As part of my GSoC 2025 application, I’ve contributed to improving the clarity and completeness of docstrings in the viz.py module. This includes refining parameter explanations, return types, and adding missing docstrings for consistency across the module.

I've opened a pull request here: #1021. Looking forward to your feedback and suggestions!

Best regards,
Anushka Sharma