A new Scheme tutorial

[Jean Abou Samra]

Hi,

Last year, after I delivered a presentation on Scheme at a
French-speaking virtual meeting of LilyPond users, I was asked
if I could write that down in tutorial form, which I did as
https://tutoriel-scheme.readthedocs.io. Over the past few days,
I've set some time apart to translate that into English.
The English version can be found here:

https://scheme-tutorial.readthedocs.io

The translation is a bit unpolished at the moment, and I didn't
proofread it yet; I indent to do that later.

I hope this can help some people on their way to learning Scheme
and LilyPond's inner workings. If you have feedback, feel free
to drop me an email.

Enjoy!

Best,
Jean