Update readme describing difficulty displayed on log lines.

README

@@ -382,6 +382,18 @@ Thread 1: 60.2 Mh/s Enabled ALIVE
 Or press any other key to continue
 
 
+The running log shows output like this:
+
+ [2012-10-12 15:38:17] Accepted 78bb4861 Diff 2/1 GPU 1 pool 6
+ [2012-10-12 15:38:17] Accepted f99b2b7a Diff 4/1 GPU 2 pool 6
+ [2012-10-12 15:38:23] Accepted af298bef Diff 4/1 GPU 0 pool 6
+ [2012-10-12 15:38:24] Accepted d04421af Diff 5/1 GPU 0 pool 6
+ [2012-10-12 15:38:25] Accepted c18e5b5b Diff 4/1 GPU 3 pool 6
+
+The 8 byte hex value are the 2nd 8 bytes of the share being submitted to the
+pool. The 2 diff values are the actual difficulty target that share reached
+followed by the difficulty target the pool is currently asking for.
+
 ---
 Also many issues and FAQs are covered in the forum thread
 dedicated to this program,