_content/doc/security/vuln: add section on vulndb bulk download

Adds section describing the new bulk download option for vulndb.

Change-Id: I347ec31a03504cafd965b342b73c641ab274753d
Reviewed-on: https://go-review.googlesource.com/c/website/+/557739
Reviewed-by: Zvonimir Pavlinovic <zpavlinovic@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
diff --git a/_content/doc/security/vuln/database.md b/_content/doc/security/vuln/database.md
index 26b75e8..88d8b31 100644
--- a/_content/doc/security/vuln/database.md
+++ b/_content/doc/security/vuln/database.md
@@ -119,6 +119,12 @@
   See [/ID/GO-2022-0191.json](https://vuln.go.dev/ID/GO-2022-0191.json)
   for a live example.
 
+### Bulk download
+
+To make it easier to download the entire Go vulnerability database,
+a zip file containing all the index and OSV files is available at
+[vuln.go.dev/vulndb.zip](https://vuln.go.dev/vulndb.zip).
+
 ### Usage in `govulncheck`
 
 By default, `govulncheck` uses the canonical Go vulnerability database at [vuln.go.dev](https://vuln.go.dev).