Add README file
diff --git a/README b/README
new file mode 100644
index 0000000..79b9f24
--- /dev/null
+++ b/README
@@ -0,0 +1,12 @@
+This library is a C interface to the Unicode Characters Database.
+It delivers most, but not all information from the UCD, the chief
+omissions are the UniHan database and (currently) the non-simple case
+transformations.
+
+If you're using this, please drop me (H. Peter Anvin <hpa@zytor.com>)
+a note; probably there will eventually be a mailing list.
+
+To compile, adjust the file MCONFIG to suit your needs, and build it
+with "make".  See the man page (libucd.3) and the header file (ucd.h)
+for API information.
+