Update example to include http3 configuration

dnscrypt-proxy/example-dnscrypt-proxy.toml

@@ -97,6 +97,13 @@ disabled_server_names = []
 force_tcp = false
 
 
+## Enable support for HTTP/3 (DoH3, HTTP over QUIC)
+## Note that, like DNSCrypt but unlike other HTTP versions, this uses
+## UDP and (usually) port 443 instead of TCP.
+
+http3 = false
+
+
 ## SOCKS proxy
 ## Uncomment the following line to route all TCP connections to a local Tor node
 ## Tor doesn't support UDP, so set `force_tcp` to `true` as well.