src/vs/base/common/strings.ts/format
export function format(value: string, ...args: any[]): string {
	if (args.length === 0) {
		return value;
	}
	return value.replace(_formatRegexp, function (match, group) {
		const idx = parseInt(group, 10);
		return isNaN(idx) || idx < 0 || idx >= args.length ?
			match :
			args[idx];
	});
}