Merge pull request #353 from DmytroChebruchan/patch-1

Update part1.asciidoc

part1.asciidoc

@@ -32,7 +32,7 @@ To do that, we present four key design patterns:
 * The <<chapter_02_repository,Repository pattern>>, an abstraction over the
   idea of persistent storage
 
-* The <<chapter_04_service_layer,Service Layer>> pattern to clearly define where our
+* The <<chapter_04_service_layer,Service Layer pattern>> to clearly define where our
   use cases begin and end
 
 [role="pagebreak-before"]