Add mising A to fg256 example in readme

Author: kodie

README.md

@@ -465,7 +465,7 @@ echo $color->ok('This is ok msg');
 ```php
 Ahc\Cli\Output\Color::style('mystyle', [
     'bg' => Ahc\Cli\Output\Color::CYAN,
-    'fg' => hc\Cli\Output\Color::fg256(57), // 256 colors can be used as well
+    'fg' => Ahc\Cli\Output\Color::fg256(57), // 256 colors can be used as well
     'bold' => 1, // You can experiment with 0, 1, 2, 3 ... as well
 ]);