shell-things/Windows/DoH

# DNS over HTTPS in Windows 11

Requires Windows 11.

* `GPO-EnforceDoH.reg` enables the group policy to require DoH. However it
  didn't seem to work for me or it allowed me to set the DNS server to not
  use DoH.

* `DohWellKnownServers` adds DoH support for multiple IPv4 & IPv6 addresses
  that Windows 11 isn't shipping by default, currently:
  * Adguard
  * Cloudflare antimalware
  * DNS0 (& Zero)
  * Mullvad
  * Mullvad Adblock
  * Quad9 ECS (Windows 11 defaults include Quad9 default)

## Configuration

Once Windows knows about the DoH servers (DohWellKnownServers.reg), DNS-over
HTTPS can be enabled for:

* All networks: `Windows-I (Settings) -> Network & Internet -> Advanced network settings -> WLAN -> View additional properties -> DNS Server assignment -> Edit`
  * Same place for Ethernet etc.
* Specific network: `Windows-I (Settings) -> Network & Internet -> WiFi -> Connected SSID -> DNS server assignment -> Edit`
  * Note: if the all networks one is configured, there is a warning about it not being used.