time: document that a marshaled time does not include location name
time: document that a marshaled time does not include location name

Fixes #28421

Change-Id: I00878ec246d5249d910f2b57749f74cfc38dbec6
Reviewed-on: https://go-review.googlesource.com/c/148117
Reviewed-by: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>

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