Fix typewriting animation interface #6
Description
Each time a user presses the play button, the text animation skips to the next message while speeding up.
Instead, the typewriting animation should finish playing on the current message. The next message should start playing only after user presses play button again.
Play button should say "START" when page loads. It should change to "NEXT" or "CONTINUE" when user presses it. Finally, it should say "REPLAY" when the last message is played.