Add an option to start typing on a new line

[Farzat07]

This is added as an option to the preset. This allows users to populate their promptline with slices while resting assured that they still have a full new line in which they can enter their commands.

Refs#35 Refs#48

[Farzat07]

If you believe the implementation could be improved, I would be more than happy to apply the changes.

I decided to keep updating the documentation till the end as I'm not sure yet if we will use this format or not. Once the approach is approved, I'd be happy to implement the documentation as well.