Add missing export

Author: Planeshifter

lib/node_modules/@stdlib/ndarray/base/lib/index.js

@@ -436,6 +436,15 @@ setReadOnly( ns, 'transpose', require( '@stdlib/ndarray/base/transpose' ) );
 */
 setReadOnly( ns, 'unary', require( '@stdlib/ndarray/base/unary' ) );
 
+/**
+* @name unaryBy
+* @memberof ns
+* @readonly
+* @type {Function}
+* @see {@link module:@stdlib/ndarray/base/unary-by}
+*/
+setReadOnly( ns, 'unaryBy', require( '@stdlib/ndarray/base/unary-by' ) );
+
 /**
 * @name unaryLoopOrder
 * @memberof ns