Highlight the synopsis and summary in --help

This doesn't cover all the binaries, but I don't know how to script
this, and I run out of steam ;)

src/network/networkctl.c

@@ -1749,8 +1749,8 @@ static int help(void) {
         if (r < 0)
                 return log_oom();
 
-        printf("%s [OPTIONS...]\n\n"
-               "Query and control the networking subsystem.\n"
+        printf("%s%s [OPTIONS...]\n\n"
+               "Query and control the networking subsystem.%s\n"
                "\nCommands:\n"
                "  list [PATTERN...]     List links\n"
                "  status [PATTERN...]   Show link status\n"
@@ -1766,7 +1766,9 @@ static int help(void) {
                "  -a --all              Show status for all links\n"
                "  -s --stats            Show detailed link statics\n"
                "\nSee the %s for details.\n"
+               , ansi_highlight()
                , program_invocation_short_name
+               , ansi_normal()
                , link
         );