Add supporting themes required for Lotusdocs

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

@@ -0,0 +1,9 @@
+var hash = {
+  start: 'end',
+  end: 'start'
+};
+export default function getOppositeVariationPlacement(placement) {
+  return placement.replace(/start|end/g, function (matched) {
+    return hash[matched];
+  });
+}