add initial bringup script

bringup.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+#
+# Run this script with a newly manufactured tRacket board connected to give it
+# a unique storage encryption key and flash the latest firmware.
+# The "tail" command will show the board's UUID; this needs to be added to the
+# server for device registration.
+
+dd if=/dev/urandom of=hmac_key bs=1 count=32
+echo "BURN" | pio pkg exec -- espefuse.py --port /dev/ttyACM0 burn_key BLOCK4 hmac_key HMAC_UP
+rm hmac_key
+pio run -t upload
+tail -F /dev/ttyACM0
+