Add web front-end and fix API issues

node_modules/rxjs/dist/cjs/internal/util/not.js

@@ -0,0 +1,8 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.not = void 0;
+function not(pred, thisArg) {
+    return function (value, index) { return !pred.call(thisArg, value, index); };
+}
+exports.not = not;
+//# sourceMappingURL=not.js.map