Deprecation of 'formatting.formatOnSave' in favor of 'editor.formatOnSave'

[DonJayamanne]

The custom setting python.formatting.formatOnSave used to enable formatting upon saving has been deprecated in favor of the standard VS Code setting.

If would you like to enable formatting upon saving, please enable the setting editor.formatOnSave within your user or workspace settings as follows:

"editor.formatOnSave": true

If you prefer to enable or disable this feature specifically for python, you could do so as follows:

"[python]":{
    "editor.formatOnSave":false
}

More information on these configuration settings cane be found here.

[DonJayamanne]

Fixes #285