Fix - Q26: What are stateful components?

[pgendre]

Hi Alex,
Thanks for Fullstack.cafe: really useful to prepare interviews :)!
A quick note regarding the following question:
Q26: What are stateful components?
The answer should be updated (as functional components can be stateful now thanks to React hooks).
The answer is actually updated on https://github.com/sudheerj/reactjs-interview-questions.