message: Provide different instructions for Mac and Windows/Linux
diff: @@ -12,9 +12,11 @@ Requirements
  **Hardware**: This library is intended to be used to program a Teensy 3.6 that is connected to a Tympan Audio Board (the Tympan in the nice black case). To fully utilize the Teensy 3.6, you will also need an external microphone, a headset or earbuds and a micro USB cable. Although the Tympan Audio Board also has an On-Board Microphone, the default programming for this device references an external microphone. If you have been provided with the 2017-04-27 Typman Getting Started.pptx, you will find it helpful to review that first for additional information related to the physical hardware setup.
  -**Arduino IDE**: To program the Tympan, you need to download and install the [Arduino IDE](https://www.arduino.cc/en/Main/Software). Download the actual Arduino IDE, don't use the online web-based editor. After installing the Arduino IDE, open the shortcut so that it fully initializes. Then, you can close it down and move to the next step, which is...
  +**Arduino IDE (Windows/Linux)**: To program the Tympan, you need to download and install the [Arduino IDE](https://www.arduino.cc/en/Main/Software). Download the actual Arduino IDE, don't use the online web-based editor. After installing the Arduino IDE, open the shortcut so that it fully initializes. Then, you can close it down and move to the next step, which is...
  -**Teensyduino Add-On**: After installing the Arduino IDE, you need to download and install the [Teensyduino Add-On](https://www.pjrc.com/teensy/td_download.html), which allows you to program the Teensy using the Arduino IDE. It'll ask you whether you want to install a bunch of libraries. You can say "yes" to them all, or you can say "yes" to just a few (like Audio, Bounce2, FreqCount, FreqMeasure, i2c_t3, SerialFlash, Snooze, and SPIFlash). It's your choice.
  +**Teensyduino Add-On (Windows/Linux)**: After installing the Arduino IDE, you need to download and install the [Teensyduino Add-On](https://www.pjrc.com/teensy/td_download.html), which allows you to program the Teensy using the Arduino IDE. It'll ask you whether you want to install a bunch of libraries. You can say "yes" to them all, or you can say "yes" to just a few (like Audio, Bounce2, FreqCount, FreqMeasure, i2c_t3, SerialFlash, Snooze, and SPIFlash). It's your choice.
  +
  +**Teensyduino (Mac)**: Recent versions of OS X do not support the Teensyduino Add-On installer, so there is a full [Teensyduino IDE](https://www.pjrc.com/teensy/td_download.html) available from the Teensy project which just needs to be downloaded and extracted from its ZIP file.
  Installing the Tympan Library
  ------------
  