Allows us to have custom PlatformIO envs and configs (#2234)

.gitignore

@@ -16,3 +16,4 @@ cmake-*
 compile_commands.json
 .venv/
 venv/
+platformio.local.ini

platformio.ini

@@ -11,6 +11,7 @@
 [platformio]
 extra_configs =
 	variants/*/platformio.ini
+	platformio.local.ini
 
 [arduino_base]
 framework = arduino