[Feature] Automatic update without cron job

I feel like it shouldn't be necessary to set up a cron job for automatic feed updating.

We already have the ability to perform a feed update by calling https://freshrss.example.net/i/?c=feed&a=actualize, and calling that URL every minute would perform a feed refresh at most once every 20 minutes.

Perhaps we could have an option to automatically call that URL every minute in the background whenever the FreshRSS page is open?