Enhance `<Image>` loading

### Description

Some of our `<Image>`s are stored in `/public/images`. Based on what's described in [Astro | Where to store images `src/` vs `public/`](https://docs.astro.build/en/guides/images/#where-to-store-images), it looks like it would be better for these images to be in `src/assets`.

Let's give it a try!