Update footer.html

Author: int64ago

_includes/footer.html

@@ -6,6 +6,7 @@
         <a href="http://jekyllrb.com/" target="_blank">jekyll</a> 驱动 /
         <a href="http://pixyll.com/" target="_blank">pixyll</a> 提供模板 /
         <a href="https://pages.github.com/" target="_blank">Github Pages</a> 托管
+        &nbsp;&nbsp;&nbsp;<a href="https://beian.miit.gov.cn/" target="_blank">蜀ICP备16004071号-1</a>
       </small>
     </div>
   </div>