How can I preserve indentation in Notes.app on OS X? Suppose I've got a text formatted like this:

To do:  
    To buy:  
        milk


I would like the Notes app to keep the indentation level as I enter a new line:

To do:  
    To buy:  
        milk
        sugar


How ever it jumps to the beginning of the next line:

To do:  
    To buy:  
        milk
sugar


Can I do anything about it? (Except using lists/bullet points?)
One solution is to write all your list items, one under the other, neglecting any indentation level. Then, you can select all the items you want to be on the same level, and press cmd+]. This will allow you to increase the indentation level.
As far as I know, auto-indentation applies just for bulled/dashed lists.