CI/DC placeholder

[saikek]

• Probably not all code changes should build Platformio code. It is possible to specify folder on which build would be triggered. (main for example)
• I saw a lot of warnings in code - maybe there is some plugin to monitor and show that as well if it matters
• It is possible to use platformio to re-define configuration there (it seems to be working for me).
  https://github.com/Bodmer/TFT_eSPI do a override of SPI configuration from platformio file like this:

build_flags =
  -DUSER_SETUP_LOADED
  -DST7735_DRIVER
  -DTFT_CS=5
  -DTFT_DC=19
  -DTFT_RST=-1