Add web front-end and fix API issues

node_modules/rxjs/dist/esm/internal/observable/concat.js

@@ -0,0 +1,7 @@
+import { concatAll } from '../operators/concatAll';
+import { popScheduler } from '../util/args';
+import { from } from './from';
+export function concat(...args) {
+    return concatAll()(from(args, popScheduler(args)));
+}
+//# sourceMappingURL=concat.js.map