Update README.md - Add: Building the Flappy Bird A.I. without LIBRARIES

[MaxRohowsky]

Description

Added Building the Flappy Bird A.I. without LIBRARIES to the Machine Learning section

Motivation and Context

It's a popular video in a niche. Most tutorials use libraries to add ai to flappy bird.
This video goes into depth by coding the net from scratch.

How Has This Been Tested?

No issues.

Types of changes

• Content Update (change which fixes an issue or updates an already existing submission)
• New Article (change which adds functionality)
• Documentation change

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have made checks to ensure URLs and other resources are valid