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 standard
    - Zero
    - Open
    - Kids
  - 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.