Merge branch 'devkit-diagram' into 'master'

Add a diagram showing positions and types of sockets/switches

See merge request Librem5/developer.puri.sm!115

Development_Environment/Boards/imx8.rst

@@ -53,6 +53,21 @@ Notably, the development board has an Ethernet port, a single USB-C port, and
 a Mini-HDMI port. The attached display does not function correctly at the
 time of writing (2018-12-09), so an external display is highly recommended.
 
+.. figure:: images/dev-board-sockets-buttons-switches.png
+   :scale: 50%
+   :alt: Port side, in order: 3.5mm audio socket, RJ45 Ethernet
+         socket, mini HDMI socket, USB C socket, micro SD card socket.
+         Kill switch side, in order: reset button, boot mode switch, camera
+         + microphone kill switch, cellular kill switch, Wi-Fi kill switch.
+         Button side, in order: smart card socket, volume down button, volume
+         up button, power button, micro SIM card socket.
+
+   The positions and types of sockets, push buttons and switches (click
+   to enlarge)
+
+See :ref:`hardware_reference` for information about the specific parts used
+for the sockets, buttons and switches.
+
 .. _devkit_test_run:
 
 Test Run