_content/security/vulndb: add instructions for requesting a CVE ID
_content/security/vulndb: add instructions for requesting a CVE ID

Change-Id: Id5bbdc7697ace66a77d5e9fbc08eb21b1d3e4c47
Reviewed-on: https://go-review.googlesource.com/c/website/+/422495
Run-TryBot: Tatiana Bradley <ed5904c3174de8861076818d9fdd7f7c949a16e6@golang.org>
Auto-Submit: Tatiana Bradley <ed5904c3174de8861076818d9fdd7f7c949a16e6@golang.org>
Reviewed-by: Julie Qiu <e6cb64861edcc38971590ff27c111e0e672de045@google.com>

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