docs: fix dtype guidance

Signed-off-by: Athan <[email protected]>

Author: kgryte

lib/node_modules/@stdlib/stats/nanmean/docs/repl.txt

@@ -12,7 +12,8 @@
         Function options.
 
     options.dtype: string (optional)
-        Output array data type. Must be a real-valued or "generic" data type.
+        Output array data type. Must be a real floating-point or "generic" data
+        type.
 
     options.dims: Array<integer> (optional)
         List of dimensions over which to perform a reduction. If not provided,