time: note that formats may parse invalid strings
time: note that formats may parse invalid strings

The existing documentation for time format constants doesn't mention
that they may parse technically-invalid strings, such as single-digit
hours when a two-digit hour is required by a specification.  This commit
adds a short warning note to that effect.

Fixes #37616

Change-Id: I6e5e12bd42dc368f8ca542b4c0527a2b7d30acaf
Reviewed-on: https://go-review.googlesource.com/c/go/+/229460
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

golang/go,CAFxX/go,nawawi/go,nawawi/go,golang/go,cloudflare/go,golang/go,nawawi/go,cloudflare/go,golang/go,golang/go,nawawi/go,akutz/go,golang/go,golang/go,CAFxX/go,nawawi/go,akutz/go,CAFxX/go,nawawi/go,akutz/go,CAFxX/go,akutz/go,nawawi/go,cloudflare/go,CAFxX/go,cloudflare/go,akutz/go,CAFxX/go,cloudflare/go,cloudflare/go,akutz/go,cloudflare/go,cloudflare/go,akutz/go,akutz/go,golang/go,CAFxX/go,nawawi/go,CAFxX/go