[CNI] Added explainer IATA codes (#21615)

* added explainer

* added iata link

* Update src/content/docs/network-interconnect/express-cni/create-interconnects.mdx

Co-authored-by: angelampcosta <[email protected]>

---------

Co-authored-by: angelampcosta <[email protected]>

Author: 2 people

src/content/docs/network-interconnect/express-cni/create-interconnects.mdx

@@ -10,7 +10,7 @@ To create a new interconnect, make sure you are logged in with Admin or higher-l
 1. Log in to the [Cloudflare dashboard](https://developers.cloudflare.com/), and select your account.
 2. Select **Interconnects**.
 3. In **Direct CNI**, select **Create new**.
-4. From the list, choose a location that suits you with **Select location**, or search for a location in the search box.
+4. From the list, choose a location that suits you with **Select location**, or search for one in the search box. In addition to city, state and country, you can also search by the [IATA airport code](https://en.wikipedia.org/wiki/IATA_airport_code) for the metro area where your data center is located.
    :::note
    If your location is not listed it means that Direct CNI is not available in your location yet. Refer to [Classic CNI](/network-interconnect/classic-cni/) to learn how you can use the classic version of Cloudflare Network Interconnect to connect your location to Cloudflare.
    :::