cook server does not support sections

[havanagrawal]

https://cooklang.org/docs/spec/#sections suggests that the spec supports adding multiple sections into a single recipe.

this is rendered correctly on https://cooklang.github.io/cooklang-rs, but not on cook server

Minimal reproducible recipe

---
title: Fruit Bowl
---

= preparation =

peel @banana

cut @apple

= assembly =

put @banana and @apple into a #bowl. 

Serve.

Rendering on cooklang-rs:

Rendering on local cook server