Fix: Replace alert with console.log in EventDispatcher example

[vamsi2246]

This PR improves the documentation in src/core/EventDispatcher.js by replacing an outdated alert() call with console.log() in the usage example.

Previously, the example used alert() to demonstrate event handling, which is discouraged as it blocks the main thread and interrupts the user experience.

Additionally, the example has been expanded to include a stop() method and a corresponding event listener, providing a more comprehensive demonstration of how to define and handle custom events.

Linked Issues
N/A

Additional context
Verified that the updated example code is valid JavaScript and correctly demonstrates the EventDispatcher functionality.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	350.28 83	350.28 83	+0 B +0 B
WebGPU	616.03 171	616.03 171	+0 B +0 B
WebGPU Nodes	614.64 170.74	614.64 170.74	+0 B +0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	482.33 117.81	482.33 117.81	+0 B +0 B
WebGPU	687.42 186.76	687.42 186.76	+0 B +0 B
WebGPU Nodes	637.26 173.94	637.26 173.94	+0 B +0 B