Add web front-end and fix API issues

node_modules/rxjs/dist/esm/internal/operators/expand.js

@@ -0,0 +1,7 @@
+import { operate } from '../util/lift';
+import { mergeInternals } from './mergeInternals';
+export function expand(project, concurrent = Infinity, scheduler) {
+    concurrent = (concurrent || 0) < 1 ? Infinity : concurrent;
+    return operate((source, subscriber) => mergeInternals(source, subscriber, project, concurrent, undefined, true, scheduler));
+}
+//# sourceMappingURL=expand.js.map