Feature request: center narrow mode text vertically

[karlc1]

Great plugin, I've been enjoying the feature where I can select a code block in visual mode and open in in narrow mode. It usually looks good in an ataraxis session, however, it can look a bit odd depending on the size of the code block and the padding settings for ataraxis. What I mean by this is for example that if I have a small padding and a text block with few lines, the narrow mode will display the text in the very top leaving huge amounts of blank space underneath.

In my opinion, it would look perfect every time if the center-most line of the displayed text appears in the vertical center of the window. It would be cool to have this as an option.