build/lib/electron.ts/darwinBundleDocumentTypes
function darwinBundleDocumentTypes(types: { [name: string]: string | string[] }, icon: string): DarwinDocumentType[] {
	return Object.keys(types).map((name: string): DarwinDocumentType => {
		const extensions = types[name];
		return {
			name,
			role: 'Editor',
			ostypes: ['TEXT', 'utxt', 'TUTX', '****'],
			extensions: Array.isArray(extensions) ? extensions : [extensions],
			iconFile: 'resources/darwin/' + icon + '.icns'
		} as DarwinDocumentType;
	});
}