Added comment about custom platformio.ini file

code/platformio.ini

@@ -1,3 +1,11 @@
+#
+# PLEASE NOTE:
+# This platformio.ini file is not standard and uses a custom feature.
+# The "include" option is not supported by the official version.
+# Check my PR for this feature here:
+# https://github.com/platformio/platformio/pull/790
+#
+
 [platformio]
 env_default = node-debug