Missing <area> in file paths

Update Section: Demonstrate the ability to use layout fallback for customizations and debugging - File fallback rule
Update Section: Determine module layout XML schema - layouts.xml, declare available page layouts

Author: portchris

2. Request Flow Processing/4. Determine the layout initialization process.md

@@ -164,7 +164,7 @@ Same as layout plus:
 
 ### layouts.xml - declare available page layouts
 
-- <module_dir>/view/<area>/layouts.xml
+- <module_dir>/view/<area_code>/layouts.xml
 - <theme_dir>/<Namespace>_<Module>/layouts.xml
 
 - base:
@@ -316,7 +316,7 @@ Collector\Library - Source of base layout files introduced by modules
     * <theme_dir>
   - when set 'module_name':
     * <theme_dir>/<module_name>/templates
-    * <module_dir>/view/<area>/templates
+    * <module_dir>/view/<area_code>/templates
     * <module_dir>/view/base/templates
 
 - View\Design\FileResolution\Fallback\Resolver\Simple::resolveFile(fileRule)