Rename PaginatedLinksPage as LinkedPage.

Mainly because it's shorter.
diff --git a/collections_test.go b/collections_test.go
index ea93421..665062b 100644
--- a/collections_test.go
+++ b/collections_test.go
@@ -75,7 +75,7 @@
 		Ints []int `mapstructure:"ints"`
 	}
 
-	err := mapstructure.Decode(page.(PaginatedLinksPage).Body, &response)
+	err := mapstructure.Decode(page.(LinkedPage).Body, &response)
 	if err != nil {
 		return nil, err
 	}