Add Gateway link

Author: maxvp

src/content/docs/cloudflare-one/policies/gateway/index.mdx

@@ -8,7 +8,7 @@ head:
     content: Gateway policies
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-Cloudflare Gateway, our comprehensive Secure Web Gateway, allows you to set up policies to inspect DNS, Network, HTTP, and Egress traffic.
+Cloudflare Gateway, our comprehensive [Secure Web Gateway](https://www.cloudflare.com/learning/access-management/what-is-a-secure-web-gateway/), allows you to set up policies to inspect DNS, Network, HTTP, and Egress traffic.
 
 - **DNS policies** inspect DNS queries. You can block domains and IP addresses from resolving on your devices. For more information on DNS filtering, refer to our [Learning Center article](https://www.cloudflare.com/learning/access-management/what-is-dns-filtering/).
 - **Network policies** inspect individual TCP/UDP/GRE packets. You can block access to specific ports on your origin server, including non-HTTP resources.