[D365BC] Add note about the preview audience limited capabilities

Business Central doesn't support installing preview apps in customer environments. At the preview stage, only the offer listing in the marketplace can be done. This behavior is documented in Business Central docs: https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/devenv-checklist-submission-faq#when-are-my-apps-ready-to-be-installed-in-my-business-central-environment

For visibility, it should be mentioned here too.

Author: qutreson

articles/marketplace/dynamics-365-business-central-availability.md

@@ -32,6 +32,9 @@ Then, when you're ready to make your offer available and remove the preview rest
 
 Select **Save draft** before continuing to the next tab in the left-nav menu, **Technical configuration**.
 
+> [!IMPORTANT]
+> Only the offer listing in the marketplace will be available in Preview. You will not be able to install the app in Business Central environment until you have completed the publishing process in Partner Center.
+
 ## Next steps
 
 - [Set offer technical configuration](dynamics-365-business-central-technical-configuration.md)