resolved: use Cloudflare public DNS server as a default fallback alon…

…gside Google one

Cloudflare public DNS service is currently the fastest one according to
https://www.dnsperf.com/#!dns-resolvers. Why not improve the experience for
systemd users using this as a default fallback nameserver?

docs/DISTRO_PORTING.md

@@ -49,8 +49,8 @@ NTP servers.
 
 ## DNS Servers
 
-By default, systemd-resolved uses the Google Public DNS servers
-`8.8.8.8`, `8.8.4.4`, `2001:4860:4860::8888`, `2001:4860:4860::8844`
+By default, systemd-resolved uses Cloudflare and Google Public DNS servers
+`1.1.1.1`, `8.8.8.8`, `1.0.0.1`, `8.8.4.4`, `2606:4700:4700::1111`, `2001:4860:4860::8888`, `2606:4700:4700::1001`, `2001:4860:4860::8844`
 as fallback, if no other DNS configuration is available.
 
 Use `-Ddns-servers=` to direct systemd-resolved to different fallback

meson_options.txt

@@ -213,7 +213,7 @@ option('dns-over-tls', type : 'combo', choices : ['auto', 'gnutls', 'openssl', '
        description : 'DNS-over-TLS support')
 option('dns-servers', type : 'string',
        description : 'space-separated list of default DNS servers',
-       value : '8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844')
+       value : '1.1.1.1 8.8.8.8 1.0.0.1 8.8.4.4 2606:4700:4700::1111 2001:4860:4860::8888 2606:4700:4700::1001 2001:4860:4860::8844')
 option('ntp-servers', type : 'string',
        description : 'space-separated list of default NTP servers',
        value : 'time1.google.com time2.google.com time3.google.com time4.google.com')