Create headings for settings pages

apps/settings/lib/Controller/AppSettingsController.php

apps/settings/lib/Controller/UsersController.php

apps/settings/src/router.js

apps/settings/tests/Controller/AppSettingsControllerTest.php

core/src/OCP/accessibility.js

core/templates/layout.user.php

dist/core-main.js

dist/core-main.js.map

dist/settings-vue-settings-apps-users-management.js

...ettings-vue-settings-apps-users-management.js.LICENSE.txt

dist/settings-vue-settings-apps-users-management.js.map