Add web front-end and fix API issues

node_modules/rxjs/dist/cjs/internal/operators/scan.js

@@ -0,0 +1,10 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.scan = void 0;
+var lift_1 = require("../util/lift");
+var scanInternals_1 = require("./scanInternals");
+function scan(accumulator, seed) {
+    return lift_1.operate(scanInternals_1.scanInternals(accumulator, seed, arguments.length >= 2, true));
+}
+exports.scan = scan;
+//# sourceMappingURL=scan.js.map