NetworkManager: add comments on {dns-none,paws-off-my-resolv,systemd-resolved}.conf

etc/NetworkManager/conf.d/dns-none.conf

@@ -1,5 +1,8 @@
 [main]
+# No managing DNS, no managing resolv.conf (implied made explicit here) and
+# don't push data to systemd-resolved either.
 dns=none
 rc-manager=unmanaged
+systemd-resolved=false
 
 # vim: filetype=NetworkManager.conf

etc/NetworkManager/conf.d/paws-off-my-resolv.conf

@@ -1,4 +1,7 @@
 [main]
+# dns=none would disable all DNS management by NetworkManager, while the goal
+# here is to just not touch my resolv.conf. This implies NetworkManager may
+# still send data to systemd-resolved.
 #dns=none
 rc-manager=unmanaged
 

etc/NetworkManager/conf.d/systemd-resolved.conf

@@ -1,6 +1,10 @@
 [main]
+# Send data to systemd-resolved
 dns=systemd-resolved
+# Even if I use systemd-resolved, I don't want NetworkManager to touch my
+# resolv.conf
 rc-manager=none
+# Implied, but made explicit
 systemd-resolved=true
 
 # vim: filetype=NetworkManager.conf