Issue #3038538 by smaz, kjay, markconroy, Dries: Complete 'Out of the box...

Issue #3038538 by smaz, kjay, markconroy, Dries: Complete 'Out of the box initiative' and add 'Umami demo' subsystem maintainers

(cherry picked from commit 4b2c32c4)

core/MAINTAINERS.txt

@@ -408,6 +408,11 @@ Transliteration
 Typed Data
 - Wolfgang Ziegler 'fago' https://www.drupal.org/u/fago
 
+Umami demo
+- Mark Conroy 'markconroy' https://www.drupal.org/u/markconroy
+- Gareth Goodwin 'smaz' https://www.drupal.org/u/smaz
+- Keith Jay 'kjay' https://www.drupal.org/u/kjay
+
 Update UI
 - ?
 
@@ -488,11 +493,6 @@ Layout Initiative
 Media Initiative
 - Janez Urevc 'slashrsm' https://www.drupal.org/u/slashrsm
 
-Out-of-the-Box Initiative
-- Mark Conroy 'markconroy' https://www.drupal.org/u/markconroy
-- Gareth Goodwin 'smaz' https://www.drupal.org/u/smaz
-- Keith Jay 'kjay' https://www.drupal.org/u/kjay
-
 PHPUnit Initiative
 - Daniel Wehner 'dawehner' https://www.drupal.org/u/dawehner
 - (provisional) Michiel Nugter 'michielnugter' https://www.drupal.org/u/michielnugter