Add chez scheme as an interpreter

[amirouche]

Add chez scheme as scheme an interpreter.

[Alhadis]

Hey there, 👋

What's "chez"? Could you please provide a link which details the existence of a Scheme interpreter named scheme?

Note that the interpreters list in languages.yml is only for programs which execute the file directly. E.g., bash for shell-scripts, perl for *.pl programs, etc.

[amirouche]

The first paragraph at https://cisco.github.io/ChezScheme/csug9.5/use.html#./use:h1:

When Chez Scheme is installed with default options, entering the command scheme at the shell's prompt starts an interactive Scheme session.

[Alhadis]

Chez Scheme Version 9.5.1 .
Copyright 1984-2017 Cisco Systems, Inc.

Been around for over 30 years. Strange that nobody thought to add it until now... :\

[lildude]

LGTM. I've changed the title to better reflect the actual change as "Update languages.yml" tells us nothing about the change 😄