Pre build script to update submodules

Fixes #36

platformio.ini

@@ -14,3 +14,4 @@ board = lolin_s2_mini
 framework = arduino
 lib_deps = 
 	bblanchon/ArduinoJson @ ^7.2.0
+extra_scripts = pre:pre_extra_script.py

pre_extra_script.py

@@ -0,0 +1,8 @@
+Import("env")
+
+if env.IsIntegrationDump():
+    # stop the current script execution
+    Return()
+
+env.Execute("git submodule update --init --recursive")
+print("✅ SUBMODULES UPDATED")