texrender plugin

% !latex
\documentclass{standalone}
\begin{document}
CONTENT
\end{document}

% !tikz
\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
CONTENT
\end{tikzpicture}
\end{document}

This enables the syntax such as this:

<latex>
   $$ \oint\frac{f(z)}{z - a} dz$$ 
</latex>
<tikz>
  \draw(0, 0) -- (1, 1)
</tikz>