[chronik-doc] Update the to final URL

Summary: This is chronik.e.cash.

Test Plan:
It's already live so we just update the references to the old URL.
Check there is no missed occurrence.

Reviewers: #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D16870