add a new angular examples in docs

[jozefRudy]

Hi,

is it worth adding turning new angular resource api into AsyncData<Result,exn> type?

export function toAsyncDataResult<T>(
  ref: ResourceRef<T | null | undefined>,
): AsyncData<Result<Option<T>, string>> {
  switch (ref.status()) {
    case "idle":
      return AsyncData.NotAsked();
    case "loading":
      return AsyncData.Loading();

    case "reloading":
    case "local": {
      // Keep showing previous data during reload
      const value = ref.value();
      return isNil(value)
        ? AsyncData.Loading() // fallback if no previous data
        : AsyncData.Done(Result.Ok(Option.Some(value)));
    }
    case "error": {
      const error = ref.error()?.message ?? "Unknown error";
      return AsyncData.Done(Result.Error(error));
    }
    case "resolved": {
      const value = ref.value();
      return isNil(value)
        ? AsyncData.Done(Result.Ok(Option.None()))
        : AsyncData.Done(Result.Ok(Option.Some(value)));
    }
  }
}

Also defining resource is nice with result type ->

export const DateSchema = z.string().refine(
  (val) => {
    const date = new Date(val);
    return Number.isFinite(date.getTime());
  },
  {
    message: "Invalid Date parameter",
  },
);

export const validate = <T>(
  schema: z.ZodType<T>,
  value: unknown,
): Result<T, string> => {
  const result = schema.safeParse(value);
  return result.success
    ? Result.Ok(result.data)
    : Result.Error(z.prettifyError(result.error));
};

  post = resource({
    params: () => ({ id: this.id(), createdAt: this.createdAt() }),
    loader: ({ params }) => {
      const id = validate(IdSchema, params.id);
      const date = validate(DateSchema, params.createdAt);
      const parameters = Result.all([id, date]);

      return parameters.match({
        Ok: ([id, date]) => firstValueFrom(queryPost(this.client, id, date)),
        Error: (error) => {
          this.snackbar.open(error, "Close", {
            duration: 5000,
          });
          throw new Error("Invalid parameters");
        },
      });
    },
  });

I think it fits quite well even with angular for people used to functional way of thinking.