style: Get emoji from github api (#1188)

* style: Get emoji from github api and remove emoji for 404

* update all emojis use github

* fix url is not unicode

* Update index.html

Author: sy-records

index.html

@@ -80,6 +80,7 @@
   </script>
   <script src="/lib/docsify.js"></script>
   <script src="/lib/plugins/search.js"></script>
+  <script src="/lib/plugins/emoji.js"></script>
   <script src="/lib/plugins/front-matter.js"></script>
   <script src="//unpkg.com/prismjs/components/prism-bash.min.js"></script>
   <script src="//unpkg.com/prismjs/components/prism-markdown.min.js"></script>