Added stopwatch

[sshah135]

Description:

This pull request introduces a new feature: the Stopwatch. The Stopwatch functionality has been implemented to enhance the versatility of the Big Clock application. Users can now seamlessly switch between Clock, Timer, and Stopwatch modes.

Changes:

New Files Added:

• stopwatch.ejs: HTML file for the Stopwatch UI.
• stopwatch.js: JavaScript file for the Stopwatch logic.

Updates to Existing Files:

• Modified server.js to include a new route for the Stopwatch.

Stopwatch Features:

• Display of hours, minutes, and seconds.
• Start, stop, and reset functionality for precise time tracking.
• Synchronized updates every second for accurate time representation.