feat: add math/base/special/gammasgnf

Author: vivekmaurya001

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

@@ -55,7 +55,7 @@ var gammasgnf = require( '@stdlib/math/base/special/gammasgnf' );
 
 #### gammasgnf( x )
 
-Returns the sign of the [gamma function][@stdlib/math/base/special/gamma].
+Returns the sign of the [gamma function][@stdlib/math/base/special/gamma] for a single precision-floating point number.
 
 ```javascript
 var v = gammasgnf( 1.0 );
@@ -137,7 +137,7 @@ for ( i = 0; i < x.length; i++ ) {
 
 #### stdlib_base_gammasgnf( x )
 
-Returns the sign of the [gamma-function][@stdlib/math/base/special/gamma].
+Returns the sign of the [gamma-function][@stdlib/math/base/special/gamma] for a single precision-floating point number.
 
 ```c
 float out = stdlib_base_gammasgnf( 1.0 );