01_Challange unexpected TSC error 'dateStyle'

[tadpole2077]

Issue Overview

Unexpected error on tsc compile.

Steps to Reproduce

error TS2353: Object literal may only specify known properties, and dateStyle does not
exist in type DateTimeFormatOptions

Issue source file: utils.js

function formatDate(date) {
    return date.toLocaleDateString("en-US", {
        dateStyle: "medium"
    });
}

Cause & Solution

Caused by using (tsconfig.js) "target": "ES6" for 01_Challange as per solution file.

dateStyle attribute of common type DateTimeFormatOptions was not added to spec until ES2020

dateStyle Spec Proposal July 2020 Stage 3