Add link to documentation in helpers config flow

[Mariusthvdb]

set up the new history_stats helper in 2024.8 and was shown this during the config flow:

It would be most helpful if that Documentation was directly linked, and take the user to the online pages while keeping the flow window open.

Like this:

as was suggested in Discord #beta

Thanks for considering

[karwosts]

Part of the way there with #21537