Rename any mentions of "Svelte Desktop" in the code to "Svelte NodeGUI"

[shirakaba]

svelte-nodegui is probably a better description of what the project is (Node-based JS runtime, with a GUI, rendered by Svelte). But svelte-desktop kinda spells out that it's a desktop app development framework. So it's a debate between describing what it is vs. what it's for.

Both Node.js and Qt can target mobile, however, so if NodeGUI ever one day targeted mobile as well, then we'd be shooting ourselves in the feet for calling it Svelte Desktop.

So let's officially call it "Svelte NodeGUI", but also include an "A.K.A. Svelte Desktop" wherever possible to communicate its value proposition. It'll also help with SEO.

I'm not sure whether there is an official way to capitalise NodeGUI, but I'd prefer to capitalise it as such (GUI being an acronym) rather than NodeGui.