Add readme

README.md

@@ -1 +1,11 @@
-# haskell-cron-test
+# haskell-cron-matcher
+
+Match current time with given cron pattern.
+
+	$ haskell-cron-matcher "10-20 * * * * *"
+
+See return code for result:
+
+* 0 - matched
+* 1 - dismatched
+* 2 - pattern parse error