CHANGES.md: add some of the new features
* New Features
* Python 3 compatibility
- StaSh now supports python 3, though some commands still need to be ported.
+ * StaSh now shows a short tip on startup
+ * `pip` now supports wheels and commandline scripts and has been improved greatly.
+ * the `python` command now has an interactive console
+ * `man` can now also show help for other topics, e.g. `man monkeypatching`
+ * the `monkeylord` command helps improving desktop compatibility by providing monkeypatches for various modules and functions (e.g. `subprocess`)
+ * `easy_config.py` allows you to easily configure your StaSh using a UI.
+ * access other filesystems using the `mount`, `umount` and `mc` commands.
+ * StaSh can now run commands specified in `sys.argv`, allowing command execution using the pythonista URL schema.
+ * And many more improvements and bugfixes everywhere.
* Command Scripts
- `cowsay.py`
- `dropbox_setup.py`
