Fix code formatting missing in 3.5 announcement (encode#4597)

mlorant · tomchristie · commit 1aa6dff0b54e · 2016-10-20T16:47:59.000+01:00
... in section ModelSerializer 'fields' and 'exclude'
diff --git a/docs/topics/3.5-announcement.md b/docs/topics/3.5-announcement.md
@@ -246,7 +246,7 @@ be deprecated at a later date.
 ### ModelSerializer 'fields' and 'exclude'
 
 ModelSerializer and HyperlinkedModelSerializer must include either a fields
-option, or an exclude option. The fields = '__all__' shortcut may be used to
+option, or an exclude option. The `fields = '__all__'` shortcut may be used to
 explicitly include all fields.
 
 Failing to set either `fields` or `exclude` raised a pending deprecation warning
