RelayBlinds usermod

This simple usermod toggles two relay pins momentarily (defaults to 500ms) when userVar0 is set.
e.g. can be used to "push" the buttons of a window blinds motor controller.

v1 usermod. Please replace usermod.cpp in the wled00 directory with the one in this file. You may upload index.htm to [WLED-IP]/edit to replace the default lighting UI with a simple Up/Down button one.
A simple presets.json file is available. This makes the relay actions controllable via two presets to facilitate control e.g. the default UI or Alexa.