Update home page content

[Bowen7]

1. Move “What about the license?” section to the top of the page. Delete the “What about the license?” title to save space
2. Alternate background colors from white to primary-contrast-background separating each section. Start with white for the section we moved to the top. After making this change, the license section on the home page should use a white background, while the license section on the support page should not. Therefore, rename the license class to ⁠tanzu_license on the support page
3. Update the description under the deleted title
4. Change title from “Commercial offerings” (plural) to “Commercial offering” (singular), update content under the title

[michaelklishin]

@Bowen7 I have invited you to be a collaborator so that you can push branches directly to this repo. It should simplify your contributions a bit :)

Thank you.