Add flags dev info

ee/config/feature_flags/development/group_managed_accounts.yml

 ---
 name: group_managed_accounts
-introduced_by_url: 
-rollout_issue_url: 
-group: 
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/9625
+rollout_issue_url:
+group: manage::access
 type: development
 default_enabled: false

ee/config/feature_flags/development/sign_up_on_sso.yml

 ---
 name: sign_up_on_sso
-introduced_by_url: 
-rollout_issue_url: 
-group: 
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/10338
+rollout_issue_url:
+group: manage::access
 type: development
 default_enabled: false