Update README.md

README.md

+# Library for Less Pain programming the STM32F411e-Discovery
+
+## Contents
+
+1. ADC.h/.c for reading potentiometer values
+2. DCMotor.h/.c for running a motordriver
+3. ExternButton.h/.c for reading the value of a button connecting a GPIO pin with GND
+4. ServoMotor.h/.c for running a servomotor
+
+## ADC.h/.c
+
+## DCMotor.h/.c
+
+## ExternButton.h/.c
+
+## ServoMotor.h/.c