Add The Typeinator > 01. Syntactic Sugar

[JoshuaKGoldberg]

PR Checklist

• [x] Addresses an existing open issue: fixes #238
• [x] That issue was marked as accepting prs
• [x] Steps in CONTRIBUTING.md were taken

Overview

Has users rewrite an announceMachine function so that it:

• Uses let and const instead of var for variables
• Uses ... spread for arguments instead of arguments
• Uses a for-of loop instead of a loop
• Uses ` template string literal concatenation instead of +

Also fixes up some testing around the project, while I'm here.