feat: add auto number for mathjax

[panda-z]

No description provided.

[olOwOlo]

Hi, thank you for your pull request.
Can I use Chinese?

• 我对 mathjax 不怎么了解，查询了下文档，看起来 extensions 不是必要的？它们是必要的吗？

• 因为 对于较长的数学公式 #32 的原因，有如下的问题

  

  \begin{equation}
    \int_0^\infty \frac{x^3}{e^x-1}\,dx = \frac{\pi^4}{15}
    \label{eq:sample}
  \end{equation}
  

  是我的姿势不对？

[panda-z]

Removed extensions.

[panda-z]

The extra horizontal scroll bar is due to an incorrect margin-left of mjx-itable. A workaround is loop over all mjx-itable and modify their margin-left.

[panda-z]

@olOwOlo I don't see the extra horizontal scroll bar in Firefox. However, it appears in Chromium.

[olOwOlo]

I don't see the extra horizontal scroll bar in Firefox. However, it appears in Chromium.

Me too...

For this theme, there is a workaround

.post .post-content .mjx-full-width {
  width: 759px;
}

[panda-z]

Another workaround is adding padding-right: 1px; for .MJXc-display

   .MJXc-display {
     overflow-x: auto;
     overflow-y: hidden;
+    padding-right: 1px;
   }

You may want to modify _content.scss to avoid the redundant horizontal scroll bar in Chrome/Chromium.