doc: Updates to the nRF91 DK firmware page

On the Updating the DK firmware using Programmer page:

* Added information about J-link driver.
* Image of Erase & write operation.
* Removed the nRF9161 images as it was replaced by
  nRF9151 images.

TECHDOC-3295

Signed-off-by: divya pillai <[email protected]>

Author: divipillai

doc/nrf/app_dev/device_guides/nrf91/images/cellularmonitor_navigationcertificatemanager_nrf9161.png

@@ -54,7 +54,14 @@ Modem firmware
 The :file:`CONTENTS.txt` file in the extracted folder contains the location and names of the different firmware images.
 
 Complete the steps in the following sections to program applications using the Programmer app from `nRF Connect for Desktop`_.
-You will need the following USB cables for this purpose:
+The nRF Connect for Desktop requires `SEGGER J-Link`_ |jlink_ver|.
+
+* On Windows, the driver comes bundled with nRF Connect for Desktop.
+* On macOS and Linux, you must install the driver manually.
+
+See the `nRF Connect for Desktop's additional requirements`_ section for more details on the SEGGER J-Link driver.
+
+You will also need the following USB cables:
 
 * nRF91x1 DK - USB-C cable
 * nRF9160 DK - micro-USB cable
@@ -205,7 +212,18 @@ To update the application firmware using the Programmer app, complete the follow
 #. Click the :guilabel:`Erase & write` button in the **DEVICE** section to program the DK.
    Do not unplug or turn off the DK during this process.
 
-   .. figure:: images/programmer_erasewrite_nrf9160dk.png
-      :alt: Programmer - Erase & write
+   .. tabs::
+
+      .. group-tab:: nRF91x1 DK
+
+         .. figure:: images/programmer_erasewrite_nrf9151dk.png
+            :alt: Programmer - Erase & write (nRF9151 DK shown)
+
+            Programmer - Erase & write (nRF9151 DK shown)
+
+      .. group-tab:: nRF9160 DK
+
+         .. figure:: images/programmer_erasewrite_nrf9160dk.png
+            :alt: Programmer - Erase & write
 
-      Programmer - Erase & write
+            Programmer - Erase & write

doc/nrf/app_dev/device_guides/nrf91/images/cellularmonitor_open_serial_terminal_nrf9161.png

@@ -398,6 +398,7 @@
 
 .. _`nRF Connect for Desktop`: https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Connect-for-desktop
 .. _`Download nRF Connect for Desktop`: https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Connect-for-desktop/Download#infotabs
+.. _`nRF Connect for Desktop's additional requirements`: https://docs.nordicsemi.com/bundle/nrf-connect-desktop/page/download_cfd.html#additional-requirements
 
 .. _`nRF Connect for Mobile`: https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Connect-for-mobile