[Entry] General: Full-stack

[not-a-ethan]

Reason/inspiration (optional)

We have a front-end and back-end entries so we need to finish it will a full-stack entry.

Entry Type (select all that apply)

New Concept Entry for Existing Topic

Code of Conduct

• [X] I agree to follow Codecademy Doc's Code of Conduct

For Maintainers

• [x] Labels added
• [ ] Issue is assigned