Update howto-configure-publisher-domain.md

Adding this comment to the doc - You are not required to keep up the resources used for verification after domain has been verified. Once the verification is done you can remove the hosted file.
Based on this thread - https://github.com/MicrosoftDocs/azure-docs/issues/53244

Author: secherka

articles/active-directory/develop/howto-configure-publisher-domain.md

@@ -82,6 +82,8 @@ If your app isn't registered in a tenant, you'll only see the option to verify a
 
 1. Click the **Verify and save domain** button.
 
+You are not required to keep up the resources used for verification after domain has been verified. Once the verification is done you can remove the hosted file.
+
 ### To select a verified domain
 
 - If your tenant has verified domains, select one of the domains from the **Select a verified domain** dropdown.