development.7: markup nits, tag spdx

Using quoted literals is a mistake in roff(7).
Please escape with \&, the zero-width-space.

Reviewed by: emaste
MFC after: 3 days

(cherry picked from commit f354ca7383f709f8380e11b2192eb62312d4139f)
(cherry picked from commit 65c70eb58bbe81b1b191cf82d0a36b9ba280b5e7)