Document git requirements for GIT_SUBMODULE_STRATEGY=recursive
Document git requirements for GIT_SUBMODULE_STRATEGY=recursive

jirutka/gitlabhq,mmkassem/gitlabhq,jirutka/gitlabhq,stoplightio/gitlabhq,dreampet/gitlab,axilleas/gitlabhq,jirutka/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,mmkassem/gitlabhq,dreampet/gitlab,dreampet/gitlab,axilleas/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,jirutka/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,iiet/iiet-git,dreampet/gitlab,axilleas/gitlabhq,stoplightio/gitlabhq,axilleas/gitlabhq