add files to ghpages
Merge branch 'gh-pages' of https://github.com/UCBdemography/DemogBerkeley
Merge branch 'gh-pages'
modify roxygen
update help
update help
update help
update help
update help
update help
update help
update help
Merge branch 'master' into gh-pages
Merge branch 'gh-pages' of https://github.com/UCBdemography/DemogBerkeley into gh-pages