V1 for compatibility to video https://youtu.be/sm1-l5-z3ag (probably no more working)
Update Video: https://youtu.be/ZFgh2KFLeGA
V2: For devices with up to 4 buttons. One pin for the switch and one pin for the LED
Analog version: for up to 8 buttons on a Wemos D1 mini. Uses the analog pin A0 for the switches and one pin per LED