Add info about new test families (8 and 9) to t/README

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

t/README

@@ -74,6 +74,8 @@ First digit tells the family:
 	5 - the pull and exporting commands
 	6 - the revision tree commands (even e.g. merge-base)
 	7 - the porcelainish commands concerning the working tree
+	8 - the porcelainish commands concerning forensics
+	9 - the git tools
 
 Second digit tells the particular command we are testing.