Add whitespace to option choice separator to allow wrapping

[timabrmsn]

For choice lists that end up being long (due to many available choices or the length of choice names), having the separator be just a | with no whitespace forces the choices to always be on a single line, which can force it outside the border of the doc.

This change turns this: Into this:

[stephenfin]

I'll get this in a release shortly. Thanks!