fix broken xrefs on abstract pages

modules/sections/pages/abstract-block.adoc

@@ -35,4 +35,4 @@ Your journey begins here.
 
 TIP: To include a quote at the beginning of a chapter in a book, wrap a quote block inside an abstract block.
 
-There's also an xref:sections:abstract.adoc[abstract section style].
+There's also an xref:abstract.adoc[abstract section style].

modules/sections/pages/abstract.adoc

@@ -13,7 +13,7 @@ The `abstract` section style must be set on the first section of the article, as
 include::example$abstract.adoc[]
 ----
 
-If you want to style a paragraph or an open block as an abstract, instead of a whole section, see the xref:blocks:abstract.adoc[abstract block style] documentation.
+If you want to style a paragraph or an open block as an abstract, instead of a whole section, see the xref:abstract-block.adoc[abstract block style] documentation.
 
 ////
 There's some sort of funkiness with book and abstract so we're putting this section on hold.