docs: Added packaging repo ref to dev guide
docs: Added packaging repo ref to dev guide

Added a link to the packaging repository in the dev guide as it could
be a useful resource.

Signed-off-by: James O. D. Hunt <348fbaadfbada55ea105602bf5609e23ac1c4898@intel.com>

clearcontainers/runtime,devimc/runtime,chavafg/runtime,devimc/runtime,chavafg/runtime,clearcontainers/runtime