_content/blog/vuln: point users to govulncheck json flag

This is done instead of pointing to vulncheck, decision on which still
has to be made.

Change-Id: I0ea010c5a9ee7107e8567ebf7b9b0b3371d5aca8
Reviewed-on: https://go-review.googlesource.com/c/website/+/459355
Run-TryBot: Zvonimir Pavlinovic <zpavlinovic@google.com>
Reviewed-by: Julie Qiu <julie@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

_content/blog/vuln.md

@@ -69,15 +69,14 @@ Govulncheck is a standalone tool to allow frequent updates and rapid iteration
 while we gather feedback from users.
 In the long term, we plan to integrate the govulncheck tool into the main Go distribution.
 
-To directly integrate vulnerability checking into other tools and processes,
-the [vulncheck](https://pkg.go.dev/golang.org/x/vuln/vulncheck) package exports govulncheck’s
-functionality as a Go API.
-
 ### Integrations
 
 It’s always better to learn about vulnerabilities as early as possible
-in the development and deployment process.
-To that end, we have integrated vulnerability detection into existing Go tools and services,
+in the development and deployment process. To integrate vulnerability
+checking into your own tools and processes, use
+[govulncheck -json](https://pkg.go.dev/golang.org/x/vuln/cmd/govulncheck#hdr-Flags).
+
+We have integrated vulnerability detection into existing Go tools and services,
 such as the [Go package discovery site](https://pkg.go.dev).
 For example, [this page](https://pkg.go.dev/golang.org/x/text?tab=versions)
 shows the known vulnerabilities in each version of golang.org/x/text.