I am using Docusaurus to generate a static website. I integrated katex using the official instructions (https://docusaurus.io/docs/next/markdown-features/math-equations).
I want to render this:
$$
\begin{aligned}
\begin{split}
u &= u^0(x,y)+z\varphi(x,y) \\
v &= v^0(x,y)+z\theta(x,y) \\
w &= w^0(x,y)
\end{split}
\tag{1.1}
\end{aligned}
$$
What I do not understand is, that the text is rendered again underneath the correctly rendered equation. What am I missing?