[website] Add icons to core page products

[zanivan]

• I have followed (at least) the PR section of the contributing guide.

Adding icons to the products on the core page of the website to ensure consistency across the website navigation. We already have them on the app bar menu and in the docs, so this will make the experience uniform throughout.

👉 https://deploy-preview-43151--material-ui.netlify.app/core/

[aarongarciah]

Looks good. I wonder if we could experience with box-less icons, as we have in the menu bar.

[zanivan]

@aarongarciah that's because we're using the InfoCard. So, I see 2 options:

1. Use a different custom component for this page, specifically
2. Tweak all instances of InfoCard

I don't know if this is worth, though, since we're aiming to move away from the concept of “core” components. But I'd vote for 1 here, if you think we should try it anyway, since InfoCard should be for information, not clicks.

[aarongarciah]

I think this is already an improvement so I'd go with it and improve it in another PR if you think it's worth it.