[REQ] add a (GH-compliant) license file

[MarcoRavich]

Hi there, 1st of all thanks for this cool list !

Since we've 'doxed' it in our HyMPS project (under the AUDIO section \ Collections page), can you please add a GH-compliant license file for it ?

Although it may sounds like a minor aspect, license file omission obviously causes an inconsistent generation of the relative badge:

(badge-generator URL: https://badgen.net/github/license/detroitsynth/awesome-open-synth)

You can easily set a standardized one through the GH's license wizard tool.

Last but not least, even if it's not an "awesome" collection, please add our project - using the official link: https://www.forart.it/HyMPS - to your list too.

Thanks in advance !