Today is already shown big at the top (temp/description/date), so
having it repeat as the first column of the daily strip was
redundant. forecast_days now means "how many upcoming days", fetching
one extra day from the API and dropping today from the strip --
high_today/low_today still come from that dropped day, unaffected.
Verified live: on a Saturday, the strip now starts at Sunday instead
of repeating Saturday.