Add web front-end and fix API issues

node_modules/rxjs/dist/cjs/internal/util/isObservable.js

@@ -0,0 +1,10 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.isObservable = void 0;
+var Observable_1 = require("../Observable");
+var isFunction_1 = require("./isFunction");
+function isObservable(obj) {
+    return !!obj && (obj instanceof Observable_1.Observable || (isFunction_1.isFunction(obj.lift) && isFunction_1.isFunction(obj.subscribe)));
+}
+exports.isObservable = isObservable;
+//# sourceMappingURL=isObservable.js.map