Update redux-saga usage docs

[Kamahl19]

Redux-saga solved (microsoft/TypeScript#30790) the long-opened issue (microsoft/TypeScript#2983) mentioned in docs https://github.com/piotrwitek/typesafe-actions#with-redux-saga-sagas , so I suppose they can be updated with better example

[piotrwitek]

Hey @Kamahl19, thanks for the heads up.

Are you able to provide an updated example?

[pybuche]

I'm also interested in this. Actually the example with saga in the README doesn't work :/

[Kamahl19]

@pybuche what do you mean doesnt work

[pybuche]

There is a typo in the code example, but I realized it only a few hours ago :)

function* addTodoSaga(action: ReturnType<typeof fetchTodosAsync.request>): Generator {
  try { // missing this line
    const response: Todo[] = yield call(todosApi.getAll, action.payload);

    yield put(fetchTodosAsync.success(response));
  } catch (err) {
    yield put(fetchTodosAsync.failure(err));
  }
}

[piotrwitek]

@pybuche created a bug for it #184, up for grabs