A zero-install, server-less implementation of remarks

This is a zero-install, HTML-resident implementation of remarks. remarks was originally a DSL, but it proves a hassle to have people install software on their systems.

Design

• Zero install for all: Both teachers and students should be able to open a remarks file in their browser.
• Save-and-resume: Manipulate the DOM rather than the JavaScript run-time. This enables saving the file once changes have been made to the document.
• Mobile-first for students: When a remarks file is finalized for student view, this student view should be friendly for view on handheld devices (tablet, or mobile).

TypeScript Style Guide

• Don't use var for non-variables, use let.
• Don't use document.createElement without a wrapper function that hence asserts a type for the created element.
• Always use ===.
• Always specify the return type of a function (especially, if it is void).