doc: samples: added documentation for new channel_sequence commands

added documentation for the new set_channel_sequence and
set_channel_sequence commands in radio_test as well as a changelog entry
for the new commands.

Signed-off-by: Thomas Johansen <thomas.johansen@nordicsemi.no>

Author: thomas-m-johansen

doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst

@@ -339,8 +339,14 @@ Peripheral samples
 
 * :ref:`radio_test` sample:
 
-  * Added the new ``start_tx_sweep_with_sleep`` shell command.
-    It allows for running a TX sweep with silent periods between each frequency.
+  * Added:
+
+    * ``start_tx_sweep_with_sleep`` shell command.
+        It allows for running a TX sweep with silent periods between each frequency.
+    * ``set_channel_sequence`` shell command.
+        It allows for setting a custom channel sequence for the ``start_tx_sweep_with_sleep`` command.
+    * ``print_channel_sequence`` shell command.
+        It prints the currently configured channel sequence.
 
 PMIC samples
 ------------

samples/peripheral/radio_test/README.rst

@@ -102,9 +102,15 @@ User interface
    * - parameters_print
      -
      - Print current delay, channel, and other parameters.
+   * - print_channel_sequence
+     -
+     - Print the custom sequence set with the set_channel_sequence command
    * - print_rx
      -
      - Print the received RX payload.
+   * - set_channel_sequence
+     - <sequence of up to 80 channels>
+     - Set a custom channel sequence for the start_tx_with_sleep command
    * - start_channel
      - <channel>
      - Start channel for the sweep or the channel for the constant carrier (in MHz, as difference from 2400 MHz).