Greasy Fork

I've updated it for the latest Wikipedia redesign.

// ==UserScript==
// @name        Wikipedia - Linkify headers
// @version     0.2.0
// @namespace   eight04.blogspot.com
// @description An userscript helping you get the url linking to specified section
// @include     https://*wikipedia.org/*
// @grant		GM_addStyle
// @compatible  firefox
// @compatible  chrome
// @compatible  opera
// ==/UserScript==

"use strict";

const headings = document.querySelectorAll("#mw-content-text div.mw-heading > :first-child[id]");

for (const heading of headings) {
	const link = document.createElement("a");
	link.innerHTML = "🔗";
	link.href = "#" + heading.id;
	link.className = "mw-headline-link";
	heading.after(link);
}

GM_addStyle(".mw-headline-link { font-size: 70%; margin-left: .2em; display:none; } .mw-heading:hover .mw-headline-link { display:inline; }");

https://gist.github.com/teohhanhui/f2486cd3ec7e392ab2691851f5041607