docs: update return annotation

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

Author: kgryte

lib/node_modules/@stdlib/math/base/special/fast/maxf/README.md

@@ -46,7 +46,7 @@ Returns the maximum single-precision floating-point number.
 
 ```javascript
 var v = maxf( 4.2, 3.14 );
-// returns 4.199999809265137
+// returns ~4.2
 ```
 
 </section>