message: (docs) - add comment about polling and requestPolicy
diff: @@ -487,6 +487,12 @@ const TodoList = ({ limit = 10 }) => {
  Which again looks a lot like `useMutation`'s tuple that contains the `executeMutation` function.
  +## Polling
  +
  +Your query can be passed an argument named `pollInterval`, this will ensure that your query
  +is reexecuted every x ms. You'll have to make sure that your `requestPolicy` for these queries
  +is `cache-and-network` or `network-only` else the data will never be refetched.
  +
  ## More examples
  More examples on how to use `urql`
  