Add some documentation for the new migration helpers
Add some documentation for the new migration helpers

t-zuehlsdorff/gitlabhq,jirutka/gitlabhq,axilleas/gitlabhq,stoplightio/gitlabhq,iiet/iiet-git,dreampet/gitlab,jirutka/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,iiet/iiet-git,htve/GitlabForChinese,dplarson/gitlabhq,axilleas/gitlabhq,mmkassem/gitlabhq,jirutka/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,iiet/iiet-git,htve/GitlabForChinese,axilleas/gitlabhq,htve/GitlabForChinese,mmkassem/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq,dplarson/gitlabhq,t-zuehlsdorff/gitlabhq,htve/GitlabForChinese,t-zuehlsdorff/gitlabhq,dplarson/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq,t-zuehlsdorff/gitlabhq,dreampet/gitlab,dplarson/gitlabhq