Merge pull request #2643 from jpadilla/master

Fix customizing field mappings link

docs/topics/3.1-announcement.md

@@ -145,7 +145,7 @@ If you're building a new 1.8 project, then you should probably consider using `U
 
 The serializer redesign in 3.0 did not include any public API for modifying how ModelSerializer classes automatically generate a set of fields from a given mode class. We've now re-introduced an API for this, allowing you to create new ModelSerializer base classes that behave differently, such as using a different default style for relationships.
 
-For more information, see the documentation on [customizing field mappings](../api-guide/serializers/#customizing-field-mappings) for ModelSerializer classes.
+For more information, see the documentation on [customizing field mappings][customizing-field-mappings] for ModelSerializer classes.
 
 ---
 
@@ -206,3 +206,4 @@ This will either be made as a single 3.2 release, or split across two separate r
 [pagination]: ../api-guide/pagination.md
 [versioning]: ../api-guide/versioning.md
 [internationalization]: internationalization.md
+[customizing-field-mappings]: ../api-guide/serializers.md/#customizing-field-mappings