setMarkdown = function (value) {
		// Clear if saving invalid value
		if (typeof value !== 'string') {
			this.set(paths.md, undefined);
			this.set(paths.html, undefined);

			return undefined;
		}

		var newMd = sanitizeHtml(value, sanitizeOptions);
		var newHtml = marked(newMd, markedOptions);

		// Return early if no changes to save
		if (newMd === this.get(paths.md) && newHtml === this.get(paths.html)) {
			return newMd;
		}

		this.set(paths.md, newMd);
		this.set(paths.html, newHtml);

		return newMd;
	}
Registers the field on the List's Mongoose Schema.

Adds String properties for .md and .html markdown, and a setter for .md
that generates html when it is updated.