Postbox / ThunderBird + ProtonMail MultiAddress Setup

This has only been tried on macOS 11. And even then I haven't run these instructions end-to-end. This is pieced together from trial & error.

This could be scripted but it's late.

	#!/usr/bin/env bash

	cat <<'EOF'

	This is where we get the `mknod` numbers from:
	* /dev/net/tun - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/devices.txt#:~:text=%2Fdev%2Fnet%2Ftun
	* /dev/tap0 = https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/devices.txt#:~:text=%2Fdev%2Ftap0

	EOF

	/**
	* Converted from https://bitbucket.org/pedro311/freshtomato-arm/raw/86fd29f5a23b1ab4b2dfb4bdae2a625fd3a134a9/release/src-rt-6.x.4708/router/nvram_arm/main.c
	* which contained the following copyright.
	*/

	/*
	* Frontend command-line utility for Linux NVRAM layer
	*
	* Copyright (C) 2012, Broadcom Corporation. All Rights Reserved.
	*

	#!/usr/bin/env bash
	#if 0
	# Original spark: https://zachholman.com/spark/
	# C implementation (reproduced below): https://git.zx2c4.com/spark/tree/spark.c
	# The first time this file is executed it will compile itself.
	echo -n "Compiling for the first time... "
	BAK=/tmp/$(basename $0).bak
	cp $0 $BAK
	sed '1s;^;//;' $0 \| gcc -o $0 -xc - -lm
	echo "Done. Original code backed up at $BAK."

	#!/usr/bin/env bash
	# https://docs.docker.com/engine/security/https/#daemon-modes
	set -eo pipefail

	if [ $UID -ne 0 ]; then
	echo "You must run this script as root."
	exit 1
	fi

	CLNT_HOST="$1"

	{
	"$schema": "http://json-schema.org/draft-04/schema#",
	"type": "object",
	"properties": {
	"environments": {
	"type": "array",
	"description": "A list of “environment” groups that contain key value pairs defining variables that are applied to each configuration in a the CMakeSettings.json.",
	"items": {
	"type": "object",
	"properties": {