doc: Add comments on the legacy status of gpgconf.conf.

--

doc/examples/gpgconf.conf

@@ -5,6 +5,10 @@
 # defaults in gpgconf and to enforce certain values for the various
 # GnuPG related configuration files.
 #
+# NOTE: This is a legacy mechanism.  The modern way is to use global
+#       configuration files like /etc/gnupg/gpg.conf which are more
+#       flexible and better integrated into the configuration system.
+#
 # Empty lines and comment lines, indicated by a hash mark as first non
 # white space character, are ignored.  The line is separated by white
 # space into fields. The first field is used to match the user or
@@ -56,7 +60,3 @@
 # "enable-ocsp" is put into the config file of gpgsm.  The latter may
 # be changed by any user.
 #-------------------------------------------------------------------
-
-
-
-