cstool: update README with more details
diff --git a/HACK.TXT b/HACK.TXT
index 8651410..522b360 100644
--- a/HACK.TXT
+++ b/HACK.TXT
@@ -17,6 +17,7 @@
 │   ├── ocaml       <- Ocaml bindings + test code
 │   └── python      <- Python bindings + test code
 ├── contrib         <- Code contributed by community to help Capstone integration
+├── cstool          <- Cstool
 ├── docs            <- Documentation
 ├── include         <- API headers in C language (*.h)
 ├── msvc            <- Microsoft Visual Studio support (for Windows compile)
@@ -35,6 +36,10 @@
 	$ ./make.sh
 	$ sudo ./make.sh install
 
+Then test Capstone with cstool, for example:
+
+	$ cstool x32 "90 91"
+
 At the same time, for Java/Ocaml/Python bindings, be sure to always use
 the bindings coming with the core to avoid potential incompatibility issue
 with older versions.