14.Countdown

Write a React component named Countdown that renders a Start button along with an initial 30-second timer.

When the user presses Start:

• The countdown begins from 30 seconds.
• The Start button disappears.
• Two new buttons appear: Pause and Stop.

Button behavior:

• Stop → Resets the timer back to 30 seconds.
• Pause → Freezes the countdown and changes its label to Resume. Clicking Resume continues the countdown.