[Feature] - Chapters 4 and 5 should be in a beginning state and not a completed state, so learners can write the code along with the lessons

[aaron-goff]

When downloading the repo, Chapters 4 and 5 are in the completed state. If someone downloads the repo and attempts to follow along with Chapters 4 and 5, this would require them to remove code in the repo, as well as set up a src and test folder.

Instead, these chapters should be in a cleaner, less completed state, so that learners can write the code along with Tariq.