Fix typo Span -> Token on Token API page
Change Span.vector_norm to Token.vector_norm.
@@ -461,7 +461,7 @@ p A real-valued meaning representation.
+cell #[code.u-break numpy.ndarray[ndim=1, dtype='float32']]
+cell A 1D numpy array representing the token's semantics.
-+h(2, "vector_norm") Span.vector_norm
++h(2, "vector_norm") Token.vector_norm
+tag property
+tag-model("vectors")
