Update the project so now its more understandable

[flameastro]

There is all what I do:

• Create a folder named assets and put all the images and the sounds in your respective folder

├───images
└───sounds

• Rename the main file KeyDrum.py to main.py, that is a more "pythonic" way to write the main file
• Rename the README.txt to README.md and add more details about the project

[flameastro]

@Moragoh