style: add decimal point

Signed-off-by: Philipp Burckhardt <[email protected]>

Author: Planeshifter

lib/node_modules/@stdlib/math/base/special/tandf/README.md

@@ -40,7 +40,7 @@ Evaluates the [tangent][trigonometric-functions] of a single-precision floating-
 
 ```javascript
 var v = tandf( 0.0 );
-// returns 0
+// returns 0.0
 
 v = tandf( 60.0 );
 // returns ~1.73