May add bottom as an option of show-notes-on-second-screen for printable handnote?

[LemonPrefect]

The speaker notes of Touyin currently only support to put the notes on the right side of a slide, which undoubtedly convenient for the screen reading, but it becomes hard for printing reading scenarios as it's hard to print such a width slides in one sheet of portrait A4 paper. Supporting to put the notes in the bottom can make it more easy for such reading scenarios.

Having read some code of touyin, it seems the feature with only right or none is implements #43.

[LemonPrefect]

Here's a picture of which the notes are in the bottom of the slides with which in one sheet of A4 paper.