Update Set-SPOTenant.md

Modified the default value for the ShowEveryoneClaim as described here that the setting has changed since March 2018 https://docs.microsoft.com/en-us/office365/troubleshoot/access-management/grant-everyone-claim-to-external-users

Author: robinmeure

sharepoint/sharepoint-ps/sharepoint-online/Set-SPOTenant.md

@@ -595,8 +595,8 @@ Note, that some SharePoint system resources such as templates and pages are requ
 
 The valid values are:  
 
-- True (default) - The Everyone claim group is displayed in People Picker.  
-- False - The Everyone claim group is hidden from the People Picker.
+- True - The Everyone claim group is displayed in People Picker. This has been the default for tenants older than March 2018  
+- False (default) - The Everyone claim group is hidden from the People Picker. This has become the new default for new tenants.
 
 ```yaml
 Type: Boolean
@@ -605,7 +605,7 @@ Aliases:
 Applicable: SharePoint Online
 Required: False
 Position: Named
-Default value: True
+Default value: False
 Accept pipeline input: False
 Accept wildcard characters: False
 ```