_content/doc/go1.18: mention go:embed all:pattern
_content/doc/go1.18: mention go:embed all:pattern

For golang/go#43854

Change-Id: I3724f620e0e2f122e7bbb615db8c0ce1b4151a8d
Reviewed-on: https://go-review.googlesource.com/c/website/+/393234
Reviewed-by: Bryan Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>
Trust: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

golang/website,golang/website,golang/website,golang/website,golang/website,golang/website,golang/website