Merge pull request MicrosoftDocs#3427 from get-itips/patch-40

Added a link to more info and a note

Author: trent-green

sharepoint/sharepoint-ps/sharepoint-online/Register-SPOHubSite.md

@@ -11,7 +11,7 @@ ms.reviewer:
 # Register-SPOHubSite
 
 ## SYNOPSIS
-Enables the hub site feature on a site to make it a hub site.
+Enables the hub site feature on a site to make it a hub site. For more information visit [SharePoint hub sites overview](https://docs.microsoft.com/sharepoint/dev/features/hub-site/hub-site-overview).
 
 
 ## SYNTAX
@@ -29,6 +29,9 @@ Use this cmdlet to register an existing site collection as a hub site.
 > [!IMPORTANT]
 > A maximum of 100 hub sites may be created per tenant, with 'unlimited' number of site collections associated to a hub site.
 
+> [!NOTE]
+> It can take up to 2-4 hours for the changes to appear.
+
 ## EXAMPLES
 
 ### Example 1