add assembly sliding window

Link: https://github.com/GeneAssembly/biosal/issues/499
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
spawn windows

Link: https://github.com/GeneAssembly/biosal/issues/500
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
add assembly block classifier

Link: https://github.com/GeneAssembly/biosal/issues/497
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
spawn block classifiers

Link: https://github.com/GeneAssembly/biosal/issues/498
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
add help page in spate

Link: https://github.com/GeneAssembly/biosal/issues/506
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>