Add callout about missing VAT field (#21568)

## Description
- The VAT field is only available for US, UK, and EU customers - other
customers who need to add a VAT field must contact support
- Context:
https://docker.slack.com/archives/C0334FHU341/p1732748355304509

## Related issues or tickets
-
[ENGDOCS-2331](https://docker.atlassian.net/browse/ENGDOCS-2331?atlOrigin=eyJpIjoiZTUyZmU2MWY0MWYyNGM5YThhNmNmMDJhMzk2OGQ3ZTEiLCJwIjoiaiJ9)

## Reviews
- [ ] Editorial review

[ENGDOCS-2331]:
https://docker.atlassian.net/browse/ENGDOCS-2331?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: sarahsanders-docker

content/manuals/billing/core-billing/history.md

@@ -44,11 +44,15 @@ You receive your invoice when the subscription renews. To verify your renewal da
 
 ### Include your VAT number on your invoice
 
+> [!NOTE]
+>
+> If the VAT number field is not available, complete the [Contact Support form](https://hub.docker.com/support/contact/). This field may need to be manually added.
+
 Update your billing information to include your VAT number:
 
 1. Sign in to Docker Hub.
 2. For user accounts, Select your avatar in the top-right corner, then **Billing**. For organizations, select the name of the organization.
-3. Select the **Payment methods and billing history** link.
+3. Select the **Billing address** link.
 4. In the **Billing Information** section, select **Update information**.
 5. In the **Tax ID** section, select the ID type and enter your VAT number.
 6. Select **Save**.