Landing Page: explore using a custom web component to cycle featured guides on page refresh

[jwcooper]

Use the current build process for showing featured images as the primary process, but on page loads, possibly pull in new featured guides randomly on refresh.

One drawback of the current process is that it can feel a little stale if we don't build for a long time.

Have to make sure the new process doesn't flash and loads quickly enough. API on learn should be heavily cached and quick.