docs: update theme preview and translation (#262)

layouts/404.html

@@ -7,12 +7,12 @@
         <h1 id="error-emoji"></h1>
         <p class="error-text">
             {{- T "pageNotFoundText" -}}&nbsp;
-            <a href="{{ .Site.Home.RelPermalink }}" title="{{ T `backToHome` }}">↩︎</a>
+            <a href="javascript:void(0);" title="{{ T `back` }}" onclick="window.history.back();"><i class="far fa-hand-point-left fa-fw"></i></a>
         </p>
     </div>
     <script type="text/javascript">
         (function() {
-            var emojiArray = ['\\(o_o)/', '(o^^)o', '(˚Δ˚)b', '(^-^*)', '(≥o≤)', '(^_^)b', '(·_·)','(=\'X\'=)', '(>_<)', '(;-;)', '\\(^Д^)/'];
+            var emojiArray = ['\\(o_o)/', '(˚Δ˚)b', '(^-^*)', '(≥o≤)', '(^_^)b', '(·_·)','(=\'X\'=)', '(>_<)', '(;-;)'];
             document.getElementById('error-emoji').appendChild(document.createTextNode(emojiArray[Math.floor(Math.random() * emojiArray.length)]));
         })();
     </script>