Simon game implemented in react.

• Add sound
• Add gameover sound
• Add highscore and score
• Make it look prettier (:
• Allow for multiple at once (possible via keyboard shortcuts).
• Figure out a good UX for telling the user they can use shortcuts to control it... If they click settings it is obvious but if they don't, they might never know.
• Potentially make the keyboard shortcuts section collapsed by default to save space and make mobile users less confused.