Documentation: DTO: specify reqd changes CMakelist

User needs to know that they will have to change the CMakelists of their sample to find their board specific overlay

Signed-off-by: Dhruva Gole <[email protected]>

Author: DhruvaG2000

Documentation/overlays.md

@@ -1,3 +1,6 @@
 # DT Overlays
 
+Once you create the overlay files inside ``variants/<BOARD_NAME>`` you need to make zephyr understand where it is or else it simply will not find the overlay file and throw errors.
+Inorder to point the build system to your overlay file, you need to modify the ``samples/CMakeLists`` file and replace ``set(DTC_OVERLAY_FILE $ENV{HOME}/zephyrproject/modules/lib/Arduino-Zephyr-API/variants/ARDUINO_NANO33BLE/arduino_nano_33_ble.overlay)`` with your path.
+
 TODO