update README

Author: dpo

README.md

@@ -25,6 +25,9 @@ This package is a modification of [swift-debugger](https://atom.io/packages/swif
 5. Hit the `Run` button. Focus moves to the first breakpoint.
 6. Use the buttons provided to navigate through your source. You can enter debugger commands directly in the command field.
 
+The current version should support Python 2.5 and higher, including Python 3.
+The Python executable to be used while debugging can be changed in the settings.
+
 ![Atom Python Debugger](https://github.com/dpo/atom-python-debugger/raw/master/screenshots/atom-python-debugger-demo.gif)
 
 ## Current limitations