Revise Homepage text and images

[theletterf]

• @open-telemetry/governance-committee We would need you to go through the current homepage copy and suggest changes in a shared document (or open a PR) so we can adapt it. Thanks!

Related:

• [Docs] homepage feature image is misleading #9046
• ...

[svrnm]

Can we not have "baggage" alongside the "real" signals? ;D