Move site name to a config

[eecue]

Instead of having the site name in the command which lives in package.json:

"postbuild": "npx svelte-sitemap --domain https://eecue.com"

Could we move it somewhere else that can be populated dynamically at runtime? I use a config file for things like this:

import { config } from '$lib/config';

Ideally I could use that to populate the domain.