[website] Change Copy on Landing page

Summary: Retained the basic idea of the copy, while removing "Milton Friedman"

Test Plan: visit e.cash and check the landing page for any errors

Reviewers: #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Subscribers: bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D16244