Update Invoke-SPOSiteDesign.md

Correction: -Identity is required parameter.

Author: aaronmi

sharepoint/sharepoint-ps/sharepoint-online/Invoke-SPOSiteDesign.md

@@ -59,7 +59,7 @@ Type: SPOSiteDesignPipeBind
 Parameter Sets: (All)
 Aliases: 
 Applicable: SharePoint Online
-Required: False 
+Required: True 
 Position: Named
 Default value: None
 Accept pipeline input: False