[e.cash] Add new social card image

Summary: Updating social card to include new tagline

Test Plan:
Check the image looks good here. There is not a great way to test the image coming through on social platforms until
after its landed since it requires an absolute path.

Reviewers: #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D16590