[content] Update homepage content

[janchild]

Update the homepage messaging of Carbon as an open, service-oriented group to support ease of use and contribution by IBMers.

The first revision would leave the existing video in place, and work to accommodate both the first-time user path and items of interest for return users.

For subsequent revisions, we will explore deeper layout work.

[jeanservaas]

Homepage design concepts: Leading with community

Banner animation sketches

Full homepage sketch

Incentivization

Meet ups

Feedback component

[shinytoyrobots]

Within the context of Sprint 4, I think the primary deliverable should be;

• Clearly defined homepage purpose (summarized in 1-2 sentences)
• Desired action/s of visitors to homepage (perhaps personas?)
• Metrics for how we might measure homepage "success"

This will then allow us to break down work into more specific pieces of design and dev work over the next couple of sprints.