Merge branch 'bvl-ff-phabricator-import' into 'master'

Add info on the phabricator_import feature flag

See merge request gitlab-org/gitlab!43723

config/feature_flags/development/phabricator_import.yml

 ---
 name: phabricator_import
-introduced_by_url: 
-rollout_issue_url: 
-group: 
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/13569
+rollout_issue_url: https://gitlab.com/groups/gitlab-org/-/epics/1197
+group: group::import
 type: development
 default_enabled: false