Add a note to /lib/map saying how to download the data files for map(1).

Reference: /n/sources/patch/applied/map-data-readme
Date: Thu Oct 12 00:51:51 CES 2006
Signed-off-by: lyndon@orthanc.ca

--- /lib/map/README	Thu Jan  1 00:00:00 1970
+++ /lib/map/README	Thu Oct 12 00:51:19 2006
@@ -0,0 +1,5 @@
+To get the map data files:
+
+  cd /lib/map
+  hget http://www.cs.dartmouth.edu/~doug/wdbii.tar.gz \
+    | gunzip | tar xv