UX: Updates the copy and layout of the landing page

[hnb-ku]

This PR adds a bit more copy to the landing page based on #36

Before:

After:

[github-actions[bot]]

All contributors have signed the CLC ✍️ ✅
_{Posted by the CLC Assistant Lite bot.}

[zicklag]

It looks like our CLC bot wants you to add the email used for the commit to your GitHub profile so that we can validate that it comes from someone who accepted the CLC.

[zicklag]

Awesome, thank you!