Describe the bug
As you can see here: https://github.com/aminalaee/sqladmin/blob/main/sqladmin/models.py#L358
We have defined a member to be equal to an external third-party class:

class X:
     form_base_class = wtforms.Form
     """Some docstrings"""

When this class is parsed the parser follows the docstrings in the third-party package and doesn't show the docstrings defined in my docs:

https://aminalaee.github.io/sqladmin/api_reference/model_admin/#sqladmin.models.ModelAdmin.form_base_class

I think either we shouldn't allow this to happen or there should be an option to control this.

As a workaround we found that we can try mkdocstrings-python package but that doesn't follow the members attribute we set and shows unwanted members:

aminalaee/sqladmin#106

To Reproduce
It's already in the description.

Expected behavior

Screenshots
If you are using pytkdocs through mkdocstrings and if relevant, please attach a screenshot.

System (please complete the following information):

• pytkdocs version [e.g. 0.2.1]
• Python version: [e.g. 3.8]
• OS: [Windows/Linux]

Additional context
Add any other context about the problem here.