Add foreign key pages to database navigation
It adds https://docs.gitlab.com/ee/development/database/foreign_keys.html and https://docs.gitlab.com/ee/development/database/add_foreign_key_to_existing_column.html to the navigation sidebar.
It adds https://docs.gitlab.com/ee/development/database/foreign_keys.html and https://docs.gitlab.com/ee/development/database/add_foreign_key_to_existing_column.html to the navigation sidebar.