Fix license

Author: yhirano55

README.md

@@ -9,3 +9,7 @@ bundle install
 
 bundle exec jekyll serve
 ```
+
+## License
+
+[Creative Commons Attribution 4.0 International License](https://creativecommons.org/licenses/by/4.0/deed.ja)

_layouts/default.html

@@ -30,7 +30,7 @@ <h2 class="project-tagline">{{ page.title }}</h2>
     <main id="content" class="main-content" role="main">
       {{ content }}
       <footer class="site-footer">
-        <span class="site-footer-credits">ruby-jp は複数名の有志の Rubyist によって運営されています<br>This website and all chat comments are Licensed Under a Creative Commons Attribution 4.0 International License.</span>
+				<span class="site-footer-credits">ruby-jp は複数名の有志の Rubyist によって運営されています<br>This website is Licensed Under a <a href="https://creativecommons.org/licenses/by/4.0/deed.ja">Creative Commons Attribution 4.0 International License</a>.</span>
       </footer>
     </main>
   </body>