add options verbose/user/confdir

README.md

@@ -1,3 +1,10 @@
 # csc : cluster ssh command
 
 simple script to execute command over ssh on remote hosts with "dialog" DEBIAN_FRONTEND
+
+## Usage
+
+Usage: csc [OPTION]... [COMMAND]
+    -v  enable verbose mode
+    -c  specify config dir, default is /$HOME/.config/csc
+    -u  specify user, default is $USER