Refactor

[jeff-eng]

• [x] Refactor footer in Main component into its own component.
• [x] questionCount state variable - refactor so it has a default value instead of setting the value upon the successful fetch of questions and getting the length of the returned array from the API.
• [x] playCount state variable - is it needed?
• [x] CSS media query duplicate code - only padding needed
• [x] start.css - min-width on .start-header__button class
• [x] main.css - height: max-content;
• [x] app.css - width and height - use 100% instead of 100vw and 100vh