MTU and Path MTU Discovery

### Example URL(s)

https://developers.cloudflare.com/cloudflare-one/team-and-resources/devices/cloudflare-one-client/deployment/mdm-deployment/path-mtu-discovery/#enable-path-mtu-discovery

### Actual Behavior

There is no mdm.xml file present. Creating a new one also doe not change the MTU from 1280. Manually changing the MTU via netsh causes Warp to not operate properly. And trying to change the Warp MTU size in the Windows Registry will not change the MTU size for Warp. I have also tried disabling ipv6 in Windows

### Expected Behavior

I can't change the MTU size in Windows despite the docs and other sources saying it should be possible in Windows.

### Additional information

_No response_

Start with the linked Path MTU Discovery documentation and compare its Windows instructions with the reported absence of mdm.xml and the behavior of netsh and the Windows Registry. Verify the supported Windows procedure and update the page so the expected MTU configuration or its limitation is clear; done means the documentation matches observed supported behavior.

Written by the indexing model from the issue text.