Add MIT license for FriendlyCaptcha

replace/google-recaptcha.md

@@ -23,5 +23,5 @@ FriendlyCaptcha is a proof-of-work based CAPTCHA in which the user's device does
 {% infobox %}
  - **Website**: friendlycaptcha.com
  - **Source code**: [GitHub](https://github.com/gzuidhof/friendly-challenge)
- - **License**: *None*
+ - **License**: [MIT](https://github.com/gzuidhof/friendly-challenge/blob/master/LICENSE.md)
 {% endinfobox %}