Added missing 'stt' command alias

plugins/sublime/README.md

@@ -12,4 +12,6 @@ Plugin for Sublime Text, a cross platform text and code editor, available for Li
 
  * If `st` is passed a directory, `cd` to it and open it in Sublime Text
 
- * If `st` is passed a file, open it in Sublime Text
+ * If `st` is passed a file, open it in Sublime Text
+
+ * if `stt` command is called, it is equivalent to `st .`, opening the current folder in Sublime Text