Update README.md

Signed-off-by: Gunj Joshi <gunjjoshi8372@gmail.com>

Author: gunjjoshi

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

@@ -59,7 +59,7 @@ Evaluates the natural [exponential function][exponential-function] as a single-p
 
 ```javascript
 var v = expf( 4.0 );
-// returns ~54.5982
+// returns ~54.598
 
 v = expf( -9.0 );
 // returns ~1.234e-4
@@ -130,7 +130,7 @@ Evaluates the natural [exponential function][exponential-function] as a single-p
 
 ```c
 float out = stdlib_base_expf( 4.0f );
-// returns ~54.5982f
+// returns ~54.598f
 
 out = stdlib_base_expf( -9.0f );
 // returns ~1.234e-4f