Clarify "Use layout builder" checkbox and drupal-layout vs section (#98)

Author: rmuit

content/2.guide/05.customized-api-output.md

@@ -7,7 +7,7 @@ A content entity can be rendered into custom elements via three methods, while t
 The three methods are:
 
 * Custom Element Display Configuration - The typically used default method. It allows fine-grained control of the output via UI. Please see below for more details.
-* Layout builder - When enabling the "Layout Builder" module for a view-mode, the layout builder may be used to allow editors to compose pages that are displayed using custom elements. Refer to the [Layout Builder guide](/guide/layout-builder) for details.
+* Layout builder - When enabling the "Layout Builder" module for a view-mode, the layout builder may be used to allow editors to compose pages that are displayed using custom elements. Refer to the [Layout Builder guide](/guide/layout-builder) for details. Activate it by ticking the "Use Layout Builder" checkbox in the UI; this checkbox is visible only after a layout is enabled through "Manage display".
 * Automatic processing - A method that allows taking full control of the output via PHP code, as outlined [here](/drupal/custom-element-processors). Activate it by ticking the "Automatic processing" checkbox in the UI.
 
 **Note**: This requires the Custom Elements UI submodule, make sure it is enabled.

content/2.guide/80.layout-builder.md

@@ -4,7 +4,7 @@ The Drupal [layout builder](https://www.drupal.org/docs/8/core/modules/layout-bu
 
 ## Rendering layouts
 
-By default, layouts are rendered using a `<drupal-layout>` custom element, such that any layout settings are forwarded to the frontend. Contained blocks may build their content using custom elements, or fallback to Drupal rendering and regular HTML.
+By default, layouts are rendered using a `<drupal-layout>` custom element for each layout section, such that any section settings are forwarded to the frontend. Contained blocks may build their content using custom elements, or fallback to Drupal rendering and regular HTML.
 
 Please see [Drupal > Providing blocks](/drupal/providing-blocks) for more details on how to provide Drupal blocks that render custom elements.