Merge #14013: [doc] Add new regtest ports in man following #10825 ports reattributions

Summary:
e8c4a1e36969d2ef816d9dfaaee979a8cf6bfffe Add new regtest ports in doc following #10825 ports reattributions (Antoine Riard)

Pull request description:

Following #10825, regtest ports for p2p connections and JSON-RPC connections have been remapped from 18333 and 18332 to 18444 and 18443. This change is not documented in the wiki or nowhere else and it's puzzling to guess why your regtest JSON-rpc connections all failed even if you're following the docs.

Tree-SHA512: e2a1b9b4059060d9ed0900c1554e124ed69ae3e4648474880795128e77c7324d68aba52e4acda2f47390a9c3d36629b777e3b8c0eb10f0e08a2b120c4119dff3

Backport of Core PR14013

Test Plan:

ninja
./bitcoin --help -help-debug
./bitcoin-cli --help

Verify changes to help text

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D5485