Make external links of readme opening a new browser window

readme.md

@@ -41,7 +41,7 @@ PHP Captcha is using GD to generate images. PHP5 and PHP7 are supported.
 
 **font**: Name of TTF font to use, default is 'Lato-Regular.ttf', you can use any TTF font you like.
 
-*Font **Lato** is GPL, OFL and Public Domain by Łukasz Dziedzic, can be found at https://www.1001freefonts.com/lato.font*
+*Font **Lato** is GPL, OFL and Public Domain by Łukasz Dziedzic, can be found at <a href="https://www.1001freefonts.com/lato.font" target="_blank">https://www.1001freefonts.com/lato.font</a>*
 
 **sessionName**: The name of the session var PHP Captcha is using to store the text from the captcha, default is `phpcaptcha`, which is accessible in `$_SESSION['phpcaptcha']`