boards: contextualelectronics: adopt new zephyr:board directive and role

This updates the documentation of all the Contextual Electronics boards
to use the new `zephyr:board::` directive.

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

boards/contextualelectronics/abc/doc/index.rst

@@ -1,7 +1,4 @@
-.. _contextualelectronics_abc:
-
-Contextual Electronics Advanced BLE Cell
-########################################
+.. zephyr:board:: contextualelectronics_abc
 
 Overview
 ********
@@ -21,12 +18,6 @@ Nordic Semiconductor nRF52840 ARM Cortex-M4F CPU and the following devices:
 * :abbr:`UART (Universal asynchronous receiver-transmitter)`
 * Quectel BG95 Modem
 
-.. figure:: img/contextualelectronics_abc.jpg
-     :align: center
-     :alt: Contextual Electronics Advanced BLE Cell
-
-     Contextual Electronics Advanced BLE Cell (Credit: Chris Gamell)
-
 More information about the board can be found at the `ABC Board website`_.
 The `Nordic Semiconductor Infocenter`_ contains the processor's information
 and the datasheet.