Function Basics: Add image that describes how parameters are passed to a function and returned from it

[nikitarevenco]

Because

Improved formatting of lesson also; moved everything relevant to assignment and added a lot of line breaks that increase readability

This PR

• Fixes lint issues
• Adds image added in Function Basics: add image file to repository #27573
• Moves articles to assignment

Issue

Closes #27539

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project Contributing Guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[JoshDevHub]

I like a lot of your changes and reorganizations here. Nice work.

Just a few fixes for trailing spaces on certain lines and one nitpick about one of the links. Everything else looks good though.