add missing files for GNU/Hurd

etc/rc.conf.GNU

@@ -0,0 +1,14 @@
+##############################################################################
+# GNU/Hurd SPECIFIC OPTIONS
+
+# This is the subsystem type. Valid options on GNU/Hurd:
+# ""        - nothing special
+# "subhurd" - Hurd subhurds (to be checked)
+# If this is commented out, automatic detection will be used.
+#
+# This should be set to the value representing the environment this file is
+# PRESENTLY in, not the virtualization the environment is capable of.
+#rc_sys=""
+# This is the number of tty's used in most of the rc-scripts (like
+# consolefont, numlock, etc ...)
+#rc_tty_number=6?