Updates fneill as codeowner for app sec dirs

.gitlab/CODEOWNERS

@@ -27,6 +27,7 @@
 /doc/api/graphql/ @msedlakjakubowski @kpaizee
 /doc/api/graphql/reference/ @kpaizee
 /doc/api/group_activity_analytics.md @fneill
+/doc/api/vulnerabilities.md @fneill
 /doc/ci/ @marcel.amirault @sselhorn
 /doc/ci/environments/ @rdickenson
 /doc/ci/services/ @sselhorn
@@ -49,6 +50,11 @@
 /doc/user/application_security/ @rdickenson
 /doc/user/application_security/container_scanning/ @ngaskill
 /doc/user/application_security/cluster_image_scanning/ @ngaskill
+/doc/user/application_security/cve_id_request.md @fneill
+/doc/user/application_security/security_dashboard @fneill
+/doc/user/application_security/vulnerabilities @fneill
+/doc/user/application_security/vulnerability_management @fneill
+/doc/user/application_security/vulnerability_report @fneill
 /doc/user/clusters/ @marcia
 /doc/user/compliance/ @rdickenson @eread
 /doc/user/group/ @msedlakjakubowski