I downloaded .zip file from here: GitHub - esp8266/Arduino: ESP8266 core for Arduino and tried to install with Arduino IDE but got this error message: "Specified folder/zip file does not contain a valid library".
It supposedly contains I2C fix I need in wire-library and which is not in the latest release (2.4.2).
So, how do I get this installed, or what do I have to do to get the fix in?