Tweak fields docs

docs/api-guide/fields.md

@@ -6,9 +6,13 @@
 >
 > — [The Zen of Python][cite]
 
+Serializer fields handle converting between primative values and internal datatypes.  They also deal with validating input values, as well as retrieving and setting the values from their parent objects.
+
+---
+
 **Note:** The serializer fields are declared in fields.py, but by convention you should import them using `from rest_framework import serializers` and refer to fields as `serializers.<FieldName>`.
 
-Serializer fields handle converting between primative values and internal datatypes.  They also deal with validating input values, as well as retrieving and setting the values from their parent objects.
+---
 
 # Generic Fields