Feedback: insert-right docstring on the vague side.

[lread]

Some helpful feedback from Slack:

Docstring for rewrite-clj.zip/insert-right:

Return zipper with item inserted to the right of the current node in zloc, without moving location. Will insert a space if necessary.

But what's an item, eh?
I'll devaguefy this and simarly vague docstrings.