Use environment extension for platformio.ini

platformio.ini

@@ -29,21 +29,8 @@ lib_ignore =
     mbedtls
 
 [env:nrf52840_mdk]
-platform = nordicnrf52
+extends = env:nrf52840_dk
 board = nrf52840_mdk
-framework = zephyr
-monitor_speed = 115200
-test_ignore = test_desktop
-build_flags = 
-    -Iinclude/tls_config
-    # For testing: -DUNITY_EXCLUDE_SETJMP_H=1
-    -DEN_INCLUDE_ZEPHYR_DEPS=1
-    -DEN_INIT_MBEDTLS_ENTROPY=0
-    -DCOVID_MEASURE_PERFORMANCE=0   # Used to measure device performance
-lib_deps =
-    prathje/exposure-notification @ ^0.1
-lib_ignore =
-    mbedtls
 
 [env:desktop]
 platform = native