docs: Update the missing docstrings on different modules (#911)

[MuggleJinx]

Add Missing Docstrings to Python Modules (#911)

This PR addresses issue #911 by adding the missing docstrings to various Python modules across the codebase. Following the project’s established docstring guidelines, the newly added docstrings enhance code readability, maintainability, and support documentation tools such as Sphinx.

Motivation and Context

Partially resolves issue #911

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds core functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)
• Example (update in the folder of example)

Implemented Tasks

• Adding and updating existing docstrings.

Checklist

Go over all the following points, and put an x in all the boxes that apply.
If you are unsure about any of these, don't hesitate to ask. We are here to help!

• I have read the CONTRIBUTION guide. (required)
• My change requires a change to the documentation.
• I have updated the tests accordingly. (required for a bug fix or a new feature)
• I have updated the documentation accordingly.