Initial
This example demonstrates the "Hello World" of VizHub's Version 3 Runtime Environment, which supports continuous hot reloading with interactive widgets. The code exports a `main` function that receives a `container` DIV element and uses its `clientWidth` and `clientHeight` for layout. It renders a simple HTML string with a font size of 217 pixels, displaying "Hello World!" centered in the container. This blank slate introduces the simplified entry point without an `index.html` file, replacing it with the exported `main` function from `index.js`.