Issue #2349559 by mortendk, jstoller: [meta] Discuss the organization of subfolders in Classy

core/themes/bartik/templates/block--search-form-block.html.twig

-{% extends "@classy/search/block--search-form-block.html.twig" %}
+{% extends "@classy/block/block--search-form-block.html.twig" %}
 {#
 /**
  * @file

core/themes/bartik/templates/block--system-menu-block.html.twig

-{% extends "@classy/system/block--system-menu-block.html.twig" %}
+{% extends "@classy/block/block--system-menu-block.html.twig" %}
 {#
 /**
  * @file