Hexo NexT 主题对数学公式的支持

# Math Formulas Render Support
math:
  # Default (false) will load mathjax / katex script on demand.
  # That is it only render those page which has `mathjax: true` in front-matter.
  # If you set it to true, it will load mathjax / katex srcipt EVERY PAGE.
  every_page: false

  mathjax:
    enable: true
    # Available values: none | ams | all
    tags: none

  katex:
    enable: false
    # See: https://github.com/KaTeX/KaTeX/tree/master/contrib/copy-tex
    copy_tex: false

<!-- This post will render the Math Equations -->
---
title: Will Render Math
mathjax: true
---
....

<!-- This post will NOT render the Math Equations -->
---
title: Not Render Math
mathjax: false
---
....

<!-- This post will NOT render the Math Equations either -->
---
title: Not Render Math Either
---
....

$ npm un hexo-renderer-marked
$ npm i hexo-renderer-pandoc

math:
  ...
  mathjax:
    enable: true

$ npm un hexo-renderer-marked

$ npm i hexo-renderer-markdown-it-plus # or hexo-renderer-markdown-it

math:
  ...
  katex:
    enable: true

$ hexo clean && hexo g -d
# or hexo clean && hexo s

$$\begin{equation}
e=mc^2
\end{equation}$$

$$\begin{equation}
\begin{aligned}
a &= b + c \\
  &= d + e + f + g \\
  &= h + i
\end{aligned}
\end{equation}$$

$$\begin{align}
a &= b + c \label{eq3} \\
x &= yz \label{eq4}\\
l &= m - n \label{eq5}
\end{align}$$

# *附 上面那种 - MarkDown 彩色字体语法：
$\color{black}{黑色(\text{black})}$
$\color{red}{红色(\text{red})}$
$\color{blue}{蓝色(\text{blue})}$

$\color{grey}{灰色}$ 
$\color{purple}{紫色}$ 
$\color{olive}{橄榄绿}$ 
$\color{teal}{蓝绿色}$ 
$\color{silver}{银色}$ 
$\color{lime}{浅绿色}$ 
$\color{navy}{藏青色}$

$\bf{加粗}$   
$\underline{下划线}$   
$\enclose{horizontalstrike}{删除线}    $
$\enclose{verticalstrike}{删\\除\\线}  $
$\enclose{updiagonalstrike}{删除线}    $
$\enclose{downdiagonalstrike}{删除线}  $
$\enclose{updiagonalstrike,downdiagonalstrike}{删除线} $
$\enclose{horizontalstrike,verticalstrike}{\;\ 删\\删除线\\\;\ 线}   $
$\enclose{updiagonalstrike,downdiagonalstrike,horizontalstrike,verticalstrike}{删除线}$