TODO in a tweet
HTML
<script src="https://unpkg.com/umbrellajs"></script>
<script>b=u("body").append(u("<input>").on("keyup",e=>13==e.keyCode&&b.append(u(`<p>${e.currentTarget.value}</p>`).on("click",e=>u(e.currentTarget).toggleClass("x")))||e.keyCode===27&&u('p').remove()))</script>
<style>.x{text-decoration:line-through}