Add web front-end and fix API issues

node_modules/rxjs/dist/esm5/internal/util/throwUnobservableError.js

@@ -0,0 +1,4 @@
+export function createInvalidObservableTypeError(input) {
+    return new TypeError("You provided " + (input !== null && typeof input === 'object' ? 'an invalid object' : "'" + input + "'") + " where a stream was expected. You can provide an Observable, Promise, ReadableStream, Array, AsyncIterable, or Iterable.");
+}
+//# sourceMappingURL=throwUnobservableError.js.map