A userscript that lets you quickly copy content on SE as markdown. Just select and pres Ctrl+Alt+M

markdownCopier.user.js

// ==UserScript==
// @name         Copy as markdown
// @namespace    http://stackexchange.com/users/4337810/
// @version      1.3
// @description  A userscript that lets you quickly copy content on SE as markdown. Just select and pres Ctrl+Alt+M
// @author       ᔕᖺᘎᕊ (http://stackexchange.com/users/4337810/)
// @match        *://*.stackexchange.com/*
// @match        *://*.stackoverflow.com/*
// @match        *://*.superuser.com/*
// @match        *://*.serverfault.com/*
// @match        *://*.askubuntu.com/*
// @match        *://*.stackapps.com/*
// @match        *://*.mathoverflow.net/*
// @require      https://unpkg.com/turndown/dist/turndown.js
// @grant        none
// ==/UserScript==

const turndownService = new TurndownService();

turndownService.addRule('div', {
    filter: ['div'],
    replacement: function(html, node) {
        return '\n ' + html;
    }
});
turndownService.addRule('script', {
    filter: ['script'],
    replacement: function(html, node) {
        return $(node).text();
    }
});

function getSelectionHtml() { //http://stackoverflow.com/a/6668159/3541881
    if (typeof window.getSelection != "undefined") {
        const sel = window.getSelection();
        if (sel.rangeCount) {
            const container = document.createElement("div");
            for (let i = 0, len = sel.rangeCount; i < len; ++i) {
                container.appendChild(sel.getRangeAt(i).cloneContents());
            }
            return container.innerHTML;
        }
    } else if (typeof document.selection != "undefined" && document.selection.type == "Text") {
        return document.selection.createRange().htmlText;
    }
}

$(document).on('keyup', function(e) {
	if (e.ctrlKey && e.altKey && e.which == 77) {
		const parsed = $.parseHTML(getSelectionHtml());
		const c = $('<div/>');

		$.each(parsed, function(i, v) {
			c.append(v);
		});

		c.find('*').filter(function() {
			return $(this).text().trim() === '';
		}).remove();

        const markdown = turndownService.turndown(c.html());
		console.log(markdown);
		prompt('Press Ctrl+C to copy markdown', markdown);
	}
});

Thanks, it works again!

Installation URL of this script for Tampermonkey:
https://gist.github.com/shu8/9203772dd22c4bc04aafebd4fc4f8ca1/raw/markdownCopier.user.js