Windows/Deployment: add Peer Cache Enterprise note

Description:
Based on community feedback and recommendation, this document can be
improved by adding notes regarding Delivery Optimization and endpoints.

Thanks to Stephen Leuthold for providing feedback and the information.
See also issue ticket "Delivery Optimization" (#4638).

Proposed changes:
- add a note containing the text suggested by SLeuthold
- add MarkDown compatibility quote spacing (33)

Caveats:
- The added text does not necessarily have to be in the form of a Note.
- The added text can, if required, be placed somewhere else on the page.

issue ticket closure or reference:

Closes #4638

windows/deployment/update/feature-update-maintenance-window.md

@@ -49,6 +49,9 @@ Use **Peer Cache** to help manage deployment of content to clients in remote loc
 
 [Enable Configuration Manager client in full OS to share content](https://docs.microsoft.com/sccm/core/clients/deploy/about-client-settings#enable-configuration-manager-client-in-full-os-to-share-content) if you have clients in remote locations that would benefit from downloading feature update content from a peer instead of downloading it from a distribution point (or Microsoft Update). 
 
+> [!NOTE]
+> In the enterprise, content delivery optimization via caching and peering solutions is imperative to mitigate the risk of interrupting business operations. It is important when downloading large payloads from the cloud (feature updates, quality updates, and so on). Most smaller organizations may have this enabled by default, but larger enterprises may need to plan an implementation to logically group different sites via AD Site or SCCM boundary group, as the egress/ingress point may be a data center in another location, rather than an internet connection local to them. Otherwise they will peer with clients potentially not in the same physical location.
+
 ### Step 4: Override the default Windows setup priority (Windows 10, version 1709 and later)
 
 If you’re deploying **Feature update to Windows 10, version 1709** or later, by default, portions of setup are configured to run at a lower priority. This can result in a longer total install time for the feature update. When deploying within a maintenance window, we recommend that you override this default behavior to benefit from faster total install times. To override the default priority, create a file called SetupConfig.ini on each machine to be upgraded in the below location containing the single section noted.