https://mannhuynh.github.io/timer/

• Event listener to watch for a click on "start" button
• Draw a full border around the timer
• Start counting down the timer
• Each time the timer counts down, update the border
• Each time the timer counts down, update the text
• If we counted down and timer reaches 0 -> reset the border
• Reset internal timer to get ready for another run.