Implement keycode_interpreter

This project is essentialy a keycode interpreter, which interprets the keycode provided to it in a text file into keyoard input.
The entire interpreter could either be implemented inside the ```interpret_keycode``` function, or helper functions could be used.
Bounty Points are awarded based on the simplicity and efficiency of your code.

In case you don't have a nondeMCU to try this out, simply copy and paste your interpreter code in the appropriate place inside ```test.c``` and compare the outputs.

For more information about the interpreter syntax, check out INTERPRETER.md

Bounty Points: 100-150