Update configure-cloud-storage.md (#1796)

Added note to highlight that the AWS S3 bucket policy is different for the EU Data Plane

site/docs/guides/configure-cloud-storage.md

@@ -34,7 +34,7 @@ You'll need to grant Estuary Flow access to your S3 bucket.
 
 2. Follow the steps
    to [add a bucket policy](https://docs.aws.amazon.com/AmazonS3/latest/userguide/add-bucket-policy.html), pasting the
-   policy below.
+   policy below. The policy below will work for the US Data Plane. If you're on the EU Data Plane, [get in touch].
    Be sure to replace `YOUR-S3-BUCKET` with the actual name of your bucket.
 
 ```json
@@ -131,4 +131,4 @@ If your bucket is for Azure, send [email protected] an email with the name of
 information you gathered per the steps above.
 Let us know whether you want to use this storage bucket to for your whole Flow account, or just a
 specific [prefix](../concepts/catalogs.md#namespace).
-We'll be in touch when it's done!
+We'll be in touch when it's done!