new collaborative example pastel patatap

[pietroppeter]

pastel patatap is a very nice example where typing a letter of the alphabet you get an animation and a sound: https://openprocessing.org/sketch/1437815

The idea is to create the overall structure and implement only a single letter and have the porting of this to be a collaborative effort. Every collaborator can port an additional letter. In the implementation there should be instructions on how to add a new letter and the list of names of collaborators should be made explicit.