added readme

assn1/README

+Prob 1 outputs the total number of directories and the total number of messages sent. 
+
+Prob 2 outputs how many messages are in the longest thread, and all threads that are of that length.
+
+Prob 3 takes in a data (Year/Month/Date) and returns a message sent on that day
+
+Prob 4 outputs hostnames and messages sent there
+
+No other programs are needed to execute the programs. Thanks!