I provided a general link to the wiki on npm software.
Also, updated the section to point to the new section on how to
create NPM packages, which is in the dev-manual.
(From yocto-docs rev: 03fd635d06d64a53ad00196919350a45942731ce)
Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>