Update README.md

Signed-off-by: Rejoan Sardar <[email protected]>

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

@@ -179,7 +179,7 @@ int main( void ) {
     for ( i = 0; i < 10; i++ ) {
         v = stdlib_base_fast_atanh( x[ i ] );
         printf( "atanh(%lf) = %lf\n", x[ i ], v );
-	}
+    }
 }
 ```