Add tmux config for running qemu with both serial ports enabled

* From Andre Richter tutorial

emulation/instructions.txt

@@ -0,0 +1,14 @@
+#########################################################
+#         Welcome to the Raspi3 Emulation with          #
+#               MiniUart and PL011UART                  #
+#                                                       #
+#                                                       #
+# 1. Use the mouse to select different panes            #
+#    and interact with the UARTS.                       #
+#                                                       #
+# 2. To quit the emulation:                             #
+#    2.1 Select the pane in which QEMU runs (this one). #
+#    2.2 CTRL-C to close qemu.                          #
+#########################################################
+
+=== QEMU ===

emulation/qemu_multi_uart.sh

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+#
+# MIT License
+#
+# Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+
+QEMU=/usr/local/Cellar/qemu/HEAD-3365de01b5-custom/bin/qemu-system-aarch64
+QEMU_OPTS=-M raspi3 -d int
+
+tmux new-session -d -s raspi3 &
+sleep 1
+tmux new-window -t raspi3:1
+tmux new-window -t raspi3:2
+
+tmux send-keys -t raspi3:0 "clear; echo '=== MiniUart ==='; bash /dev/ptmx" C-m
+tmux send-keys -t raspi3:1 "clear; printf '=== PL011 Uart ===\n\n';bash /dev/ptmx" C-m
+
+FIRST=$(ps aux | grep ptmx | sort | awk '{print $7}' | sed '1q;d')
+SECOND=$(ps aux | grep ptmx | sort | awk '{print $7}' | sed '2q;d')
+
+tmux send-keys -t raspi3:2 "clear; cat emulation/instructions.txt && ${QEMU} ${QEMU_OPTS} -kernel kernel8.img -serial /dev/$SECOND -serial /dev/$FIRST && tmux kill-session" C-m
+
+tmux join-pane -s raspi3:0 -t 2
+tmux join-pane -s raspi3:1 -t 2
+
+tmux select-pane -t 1
+tmux attach-session -t raspi3