Docs: add microphone folder (#12633)

Author: Capri2014

docs/specs/Microphone/Re_Speaker_USB_Mic_Array_Guide.md

@@ -0,0 +1,14 @@
+# Apollo 6.0 Microphone Installation
+
+### Supported Devices
+
+The Re-Speaker USB Mic Array
+https://wiki.seeedstudio.com/ReSpeaker-USB-Mic-Array/
+
+![Microphone](images/ReSpeaker-USB-Mics-box-preview.jpg)
+
+### Connection
+Use the provided USB cable and connect the microphone to a USB port on the machine which is running Apollo. A USB extension cable may be needed depending on the application.
+
+### Setup
+Follow the instructions provided [here](https://wiki.seeedstudio.com/ReSpeaker-USB-Mic-Array/#update-firmware) to update the firmware on the ReSpeaker to `48k_6_channels_firmware.bin`