How to remove github pages extra code from a page?

Question

JavaScript

I posted the page on github pages , and the code was added there,

this code is not visible even through "viewing the page code", only through the inspector.
Everything would be fine if this shit code didn’t interrupt the bootstrap styles, it’s really a mess from the page.
How to cure it?
ps figured out that this is a 404 page pushed inside my page, but what ... is not clear. I don't know how to fix it :(

Answer 1

solved the problem, the whole cant was in the font cache script, it accessed a non-existent file

<script>
        !function () {
            function e(e, t, n) {
                e.addEventListener ? e.addEventListener(t, n, !1) : e.attachEvent && e.attachEvent("on" + t, n)
            }

            function t(e) {
                return window.localStorage && localStorage.font_css_cache && localStorage.font_css_cache_file === e
            }

            function n() {
                if (window.localStorage && window.XMLHttpRequest)
                    if (t(o)) a(localStorage.font_css_cache);
                    else {
                        var n = new XMLHttpRequest;
                        n.open("GET", o, !0), e(n, "load", function () {
                            4 === n.readyState && (a(n.responseText), localStorage.font_css_cache = n.responseText, localStorage.font_css_cache_file = o)
                        }), n.send()
                    } else {
                    var c = document.createElement("link");
                    c.href = o, c.rel = "stylesheet", c.type = "text/css", document.getElementsByTagName("head")[0].appendChild(c), document.cookie = "font_css_cache"
                }
            }

            function a(e) {
                var t = document.createElement("style");
                t.innerHTML = e, document.getElementsByTagName("head")[0].appendChild(t)
            }

            var o = "_fonts.css";
            window.localStorage && localStorage.font_css_cache || document.cookie.indexOf("font_css_cache") > -1 ? n() : e(window, "load", n)
        }();
    </script>

so guys, check all the paths, I personally didn’t like the situation, because of one wrong path, a whole page 404 o_O was loaded on the site