He’s provided a wiring diagram in the repository along with the Arduino code for the ESP8266, ... [Shyam] reads the humidity and temperature data from the DHT11 sensor, ...

I’ve tried the DHT11 sensor modules at both Vcc 3.3V and 5.0V, and at both voltages the humidity values are bad. dfrobot has introduced a V2 DHT11 sensor module that changes the 10K pull-up to 4.7K.