fix(post): fix mathjax tutorial

_config.theme.yml

@@ -128,6 +128,8 @@ widgets:
         avatar:
         # Email address for the Gravatar to be shown in the profile widget
         gravatar:
+        # Whether to show avatar image rounded or square
+        avatar_rounded: false
         # Path or URL for the follow button
         follow_link: 'http://github.com/ppoffice'
         # Links to be shown on the bottom of the profile widget

source/_posts/plugin/MathJax.md

@@ -20,15 +20,14 @@ plugins:
     mathjax: true # options: true, false
 ```
 <!-- more -->
-For further MathJax configurations, please edit `<theme folder>/layout/plugin/scripts.ejs`:
-```html
-    <% if (theme.plugins.mathjax) { %>
-        <!-- Edit here -->
-        <script type="text/x-mathjax-config">
-            MathJax.Hub.Config({ tex2jax: { inlineMath: [['$','$'], ['\\(','\\)']] } });
-        </script>
-        <%- js('https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-MML-AM_CHTML') %>
-    <% } %>
+For further MathJax configurations, please edit `&lt;theme folder&gt;/layout/plugin/mathjax.ejs`:
+
+```js
+document.addEventListener('DOMContentLoaded', function () {
+    MathJax.Hub.Config({
+        // Edit here
+    });
+});
 ```
 
 ### TeX and LaTeX input