Add "Stock Ranking" link to Qiita's tags page

qiita-stock-ranking-link.user.js

// ==UserScript==
// @name        Qiita Stock Ranking Link
// @description Add "Stock Ranking" link to Qiita's tags page
// @namespace   https://gist.github.com/tkrkt
// @include     http://qiita.com/tags/*
// @version     2
// @grant       none
// ==/UserScript==

const tag = document.querySelector('h1.tagShowHeader_name').textContent;
const encodedTag = encodeURIComponent(tag);
const utf8 = tag.length === encodedTag.length ? '' : 'utf8=%E2%9C%93&';
const container = document.querySelector('section.tagShowLikeRanking');

if (container) {
  container.innerHTML += 
`<p class="text-right">
  <a href="/search?${utf8}sort=stock&q=tag%3A${encodedTag}">
    ストック数の多い投稿を見る
    <i class="fa fa-angle-double-right"></i>
  </a>
</p>`;
}