fix for Task-2-Buttons

	modified:   Task-2-Buttons/inc/main.h
	modified:   Task-2-Buttons/src/main.c
Merge pull request #3 from rktrlng/buttonsfix

fix for Task-2-Buttons
Added example for DHT
added example for DHT21 sensor
Fixed DHT21 lib
Fixed Task 10
Added exampls for stepper motor and ACD