Or even easier to make a userscript: https://openuserjs.org/
// ==UserScript==
// @name HN Avatars in 357 bytes
// @description Annotated avatars on all HN comments.
// @author tomxor (https://news.ycombinator.com/user?id=tomxor)
// @namespace https://news.ycombinator.com/item?id=30668137
// @include https://news.ycombinator.com/item*
// @include https://news.ycombinator.com/user*
// @grant none
// @version 1.0.0
// ==/UserScript==
[js goes here]