Add tutorial metadata

doc/tutorials/index.md

 ---
 stage: none
 group: unassigned
-info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+info: For assistance with this tutorials page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments-to-other-projects-and-subjects.
 ---
 
 # Learn GitLab with tutorials

doc/tutorials/make_your_first_git_commit.md

 ---
 stage: none
 group: unassigned
-info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+info: For assistance with this tutorial, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments-to-other-projects-and-subjects.
 ---
 
 # Make your first Git commit