applications: serial_lte_modem: Add removal note

Adding note that SLM will be removed before the next NCS release.

Signed-off-by: Tommi Rantanen <[email protected]>

Author: trantanen

applications/serial_lte_modem/README.rst

@@ -3,6 +3,11 @@
 Serial LTE modem
 ################
 
+.. note::
+
+   The Serial LTE Modem application will be removed before the next |NCS| release.
+   It will be replaced by the new Serial Modem, which is an add-on released separately from the `Serial-Modem`_ repository.
+
 The Serial LTE Modem (SLM) application can be used to emulate a stand-alone LTE modem on an nRF91 Series device.
 The application accepts both the modem-specific AT commands and proprietary AT commands.
 The AT commands are documented in the following guides:

doc/nrf/links.txt

@@ -54,6 +54,7 @@
 .. _`TF-M sample incompatibility issue`: https://github.com/zephyrproject-rtos/zephyr/issues/34658
 
 .. _`Asset-Tracker-Template`: https://github.com/nrfconnect/Asset-Tracker-Template
+.. _`Serial-Modem`: https://github.com/nrfconnect/ncs-serial-modem
 
 .. _`hello-nrfcloud v2.0.1`: https://github.com/hello-nrfcloud/firmware/releases/tag/v2.0.1