Move the build instructions into the arduino boards.txt file

bin/kaleidoscope-builder

@@ -147,11 +147,16 @@ prepare_to_flash () {
         compile
         size
     fi
+ 
+    flashing_instructions=$(get_arduino_pref 'build.flashing_instructions')
 
-    echo "To update your keyboard's firmware, hold down the 'Prog' key on your keyboard,"
-    echo "and then press 'Enter'."
+    if [ "x${flashing_instructions}x" == "xx" ]; then
+	flashing_instructions="If your keyboard needs you to do something to put it in flashing mode, do that now."
+    fi
+
+    printf '%b\n\n' "${flashing_instructions}"
     echo ""
-    echo "When the 'Prog' key glows red, you can release it."
+    echo "When you're ready proceed, press 'Enter'."
     echo ""
 
     # We do not want to permit line continuations here. We just want a newline.

etc/kaleidoscope-builder.conf

@@ -59,6 +59,14 @@ find_device_vid_pid() {
 }
 
 
+get_arduino_pref() {
+	pref=$1
+	# Strip the preference name. And then strip leading and trailing quotations
+	MESSAGE=$(dump_arduino_prefs | grep ${pref}= | sed -e s/^${pref}=// -e 's/^"//' -e 's/"$//')
+	echo $MESSAGE
+}
+
+
 dump_arduino_prefs() {
 # SKETCH and -build-path in this command are here because of a bug introduced in Arduino 1.8.10
 # https://github.com/arduino/arduino-builder/issues/341