document.addEventListener("DOMContentLoaded", function(event) {
    /*
        Нумерованные заголовки
     */
    var headers = document.querySelectorAll('.article-numbered-header')


    headers.forEach(function (header, idx) {
        let text = header.innerText;

        let partCount = idx + 1
        let anchorName = 'article-part-' + partCount;
        let anchor = '<a name="'+ anchorName +'" class="article-part-anchor">'+ partCount +'/</a>';

        header.insertAdjacentHTML('afterbegin', anchor);      // перед элементом - beforebegin
    })
})