Basically when clicked on src/icons/Icon.svelte which inside it is a component which is actually just a simple svg icon, it opens up a new tab to preview the svg representor of how the Icon.svelte actually looks.
Just for more simplification, you click on src/icons/Icon.svelte, you will see a preview render of the svg right beside it.
Have vsce installed
npm install -g @vscode/vsce
Build command:
vsce package