Markdown line breaks for Rd lines ending with latex markup

[mannau]

rd2markdown introduces line breaks (or does not remove newlines) if these lines end with latex blocks, e.g. \code{mycode}.

For example, the following Rd description:

\description{
This is a demo function adding two numbers. Let's see how \block{bla}
we
can \code{bla}
deal
with
line
breaks.
}

is translated into the following markdown output:

This is a demo function adding two numbers. Let's see how \block{bla}

we can `bla`

deal with line breaks.