Only UTC timezone for ISO 8601 #30
Description
Hello!
I use humantime-serde to work with json, it works fine!
But I was a bit confused with it behavior with ISO 8601 formatted strings without timezone.
Strings like that: "2022-07-12T12:01:48" are interpreted like UTC time zone.
After that I checked the documentation for rfc3339.
There are the same additional notices for all rfc3339 functions: "The value is always UTC and ignores system timezone".
Maybe this crucial information could be noticed in 'Features:' for rfc3339 ?
It could save time for many careless(like me) developers
I greatly would appreciate your response and time taken to write it. =)