[MCN] Added GCP to the changelog (#16119)

* added gcp to changelog

* changed title from overview to prod namer

* refined text

Author: marciocloudflare

src/content/changelogs/magic-cloud-networking.yaml

@@ -5,6 +5,10 @@ productLink: "/magic-cloud-networking/"
 productArea: Cloudflare One
 productAreaLink: /cloudflare-one/changelog/
 entries:
+- publish_date: '2024-08-14'
+  title: GCP on-ramps
+  description: |-
+    Magic Cloud Networking supports Google Cloud Platform.
 - publish_date: '2024-07-01'
   title: Closed beta launch
   description: |-

src/content/docs/magic-cloud-networking/index.mdx

@@ -1,5 +1,5 @@
 ---
-title: Overview
+title: Magic Cloud Networking
 pcx_content_type: overview
 sidebar:
   order: 1