Update README.md

Author: irishpatrick

README.md

@@ -1,3 +1,14 @@
 # pico-servo
 
-## Not working quite yet... :(
+A simple C library for controlling servos using a Raspberry Pi Pico
+
+## How to Build
+`mkdir build && cd build`<br>
+`cmake .. && make`
+
+Note that PICO_SDK_PATH must point to where your SDK is installed.
+
+## How to Use
+
+`#include "pico_servo.h"` In your code.<br>
+pass `-lpico-servo` when compiling