Add supporting themes required for Lotusdocs

themes/hugo-mod-jslibs-dist/popperjs/package/lib/dom-utils/getHTMLElementScroll.js

@@ -0,0 +1,6 @@
+export default function getHTMLElementScroll(element) {
+  return {
+    scrollLeft: element.scrollLeft,
+    scrollTop: element.scrollTop
+  };
+}