docs: update copy

Signed-off-by: Athan <kgryte@gmail.com>

Author: kgryte

lib/node_modules/@stdlib/stats/base/ndarray/sdsnanmeanors/docs/repl.txt

@@ -9,7 +9,7 @@
 
     If provided an empty ndarray, the function returns `NaN`.
 
-    If every indexed element is `NaN`, the function returns `NaN`.
+    If every element is `NaN`, the function returns `NaN`.
 
     Parameters
     ----------