add rdoc for assign_contributors_to_commits_with_none
add rdoc for assign_contributors_to_commits_with_none

maclover7/rails-contributors,maclover7/rails-contributors,amitsuroliya/rails-contributors,gitlabhq/gitlab-contributors,fxn/rails-contributors,amitsuroliya/rails-contributors,gitlabhq/gitlab-contributors,fxn/rails-contributors,fxn/rails-contributors,maclover7/rails-contributors,gitlabhq/gitlab-contributors,gitlabhq/gitlab-contributors,amitsuroliya/rails-contributors,fxn/rails-contributors,maclover7/rails-contributors,amitsuroliya/rails-contributors