Update esignature-setup.md

Adding details on how long the setup should take.

Author: aoifemcd1

microsoft-365/syntex/esignature-setup.md

@@ -53,6 +53,9 @@ To let people in your organization use SharePoint eSignature, follow these steps
 
 5. On the **eSignature** panel, select **Let people in your organization use eSignature**.
 
+Once configured, various background processes will be initiated to integrate the feature seamlessly into your existing Microsoft 365 tenant and services - these include tasks such as data synchronization, configuration updates, and performance optimizations.  SharePoint eSignature will be operational within 24 hours of being enabled.
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 ### Add other signature providers
 
 To select which signature providers to use, follow these steps.