Add urls and group information for progressive delivery feature flags

config/feature_flags/development/feature_flags_new_version.yml

 ---
 name: feature_flags_new_version
 introduced_by_url: 
-rollout_issue_url: 
-group: 
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/258831
+group: group::progressive delivery
 type: development
 default_enabled: true

ee/config/feature_flags/development/feature_flags_legacy_read_only.yml

 ---
 name: feature_flags_legacy_read_only
 introduced_by_url: 
-rollout_issue_url: 
-group: 
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/240985
+group: group::progressive delivery
 type: development
 default_enabled: true

ee/config/feature_flags/development/feature_flags_legacy_read_only_override.yml

 ---
 name: feature_flags_legacy_read_only_override
-introduced_by_url: 
-rollout_issue_url: 
-group: 
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40431
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/240985
+group: group::progressive delivery
 type: development
 default_enabled: false