Update metadata formatting

Update Database group metadata formatting for doc pages

doc/architecture/blueprints/database/scalability/patterns/read_mostly.md

 ---
 stage: Enablement
-group: database
+group: Database
 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
 comments: false
 description: 'Learn how to scale operating on read-mostly data at scale'

doc/architecture/blueprints/database/scalability/patterns/time_decay.md

 ---
 stage: Enablement
-group: database
+group: Database
 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
 comments: false
 description: 'Learn how to operate on large time-decay data'