Checklist:

• I have read and followed the contribution guidelines.
• I have read and followed the how to open a pull request guide.
• My pull request targets the main branch of freeCodeCamp.
• I have tested these changes either locally on my machine, or GitHub Codespaces.

Closes #69298

Add Section Headers:

## Parent and Child Classes

## The extends Keyword

## Using `super()`

## Advantages of Inheritance