src/assets/js/javascript.js
function replaceLink(target) {
        var lang = QueryString.parse(location.search).lang;
        if (lang) {
            target = target || $("body");
            target.find("a").each(function () {
                var href = $(this).attr("href"),
                    query = QueryString.parse(href);

                if (href.indexOf("javascript:") !== 0
                    && href.indexOf("http") !== 0
                    && href.indexOf("#") !== 0
                    && !query.lang) {

                    href = QueryString.setUrl(href, { lang: lang });

                    $(this).attr("href", href);
                }
            })
        }
    }
function replaceLink(target) {
        var lang = QueryString.parse(location.search).lang;
        if (lang) {
            target = target || $("body");
            target.find("a").each(function () {
                var href = $(this).attr("href"),
                    query = QueryString.parse(href);

                if (href.indexOf("javascript:") !== 0
                    && href.indexOf("http") !== 0
                    && href.indexOf("#") !== 0
                    && !query.lang) {

                    href = QueryString.setUrl(href, { lang: lang });

                    $(this).attr("href", href);
                }
            })
        }
    }
Add ?lang=[lang] in the URL *