_content/doc/fuzz: add link to OSS Fuzz docs
_content/doc/fuzz: add link to OSS Fuzz docs

Change-Id: I433d5947f64e099afe1683f81831eb7a5a7a3294
Reviewed-on: https://go-review.googlesource.com/c/website/+/388415
Run-TryBot: Julie Qiu <8d32267b6b4884cf35adeaccde2b6857ae11aace@golang.org>
Trust: Julie Qiu <e6cb64861edcc38971590ff27c111e0e672de045@google.com>
Run-TryBot: Julie Qiu <e6cb64861edcc38971590ff27c111e0e672de045@google.com>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: DO NOT USE <87e9c6d529889242b7e184afb632328636553ab4@google.com>

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