Cron help on the UI

[igorsantos07]

Checklist

• I have filled out the template to the best of my ability.
• This only contains 1 feature request (if you have multiple feature requests, open one feature request for each feature request).
• This issue is not a duplicate feature request of previous feature requests.

Is your feature request related to a problem? Please describe.

The cron idea was simply AWESOME. I guess it was easy to implement and allows us a LOT of flexibility 👏 👏 👏

That said, I have two docs suggestions.

Describe the solution you'd like

1. the descriptive text only shows during setup. It should be mentioned as well when editing/creating a sensor.
2. Only people experienced with cron know how to write its string. But it's quite simple to understand as well, so I would suggest linking from the popup to some generator tool, such as https://crontab.cronhub.io.

Describe alternatives you've considered

That was the first tool I found, and it worked fine for me, but not sure if you could find a "non-sponsored" one (or if you even care about it). Whatever the tool is, I would say it's paramount to include some way to help users build the cron string, even if it's just a docs link.

Additional context

Keep rocking! You'll get a coffee cup once exchange rates get a bit more favorable 😂

[danieldotnl]

Thank you for the encouragement and feedback. It would be awesome if you could create a PR for your suggestions for the Readme!