Print GitHub markdown files

gitprint.js

document.querySelector('#readme').setAttribute('style', 'position: absolute; top: 0; left: 0; right: 0; bottom: 0; z-index: 100; background-color: white')
document.querySelector('body').appendChild(document.querySelector('#readme'))
window.print()

I ran the suggestion by @alshdavid through a minifier and set it as a bookmark in my browser.

javascript:(function(){const styleElement=document.createElement("style");styleElement.innerHTML="\n  * {\n    font-family: Segoe UI, Helvetica, Arial, sans-serif, Apple Color Emoji, Segoe UI Emoji;\n  }\n\n  ins {\n    display: block;\n    page-break-after: always;\n  }\n";const insElements=Array.from(document.querySelectorAll("ins"));for(const e of insElements){const n=e.parentNode;n.parentNode.insertBefore(e,n.nextSibling),n.parentNode.removeChild(n)}document.head.appendChild(styleElement),document.body.innerHTML=document.querySelector("#readme").innerHTML;})();

Copy and paste it into a bookmark entry and click it to activate it on whatever readme file you're looking at.