documentation: add actor guidelines

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
documentation: add paper about decomposition

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
argonnite: use large messages

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>