[Anaytics]Update main-dashboard.mdx (#22454)

Let's refer it to more info on The Cloudflare global network.

Author: nenizera

src/content/docs/analytics/network-analytics/understand/main-dashboard.mdx

@@ -143,7 +143,7 @@ Expand each row to display event details, including the full packet headers and
 
 ## Data center country/Source data center
 
-Displays the top source Cloudflare data centers where the displayed traffic was ingested. The same card can also display the country associated with these top source data centers.
+Displays the top source [Cloudflare data centers](https://www.cloudflare.com/en-gb/network/) where the displayed traffic was ingested. The same card can also display the country associated with these top source data centers.
 
 To switch between **Data center country** and **Source data center** information, use the dropdown in the card.