Some fetched description texts result in yaml parse error

[xnhp]

Hi, thanks for creating this awesome plugin!

Consider the following embed yaml

```cardlink
url: https://math.stackexchange.com/a/1656465
title: "How can I show that a function is non-decreasing"
description: "I have the following function:$$F(x)=\begin{cases} \dfrac{x}{x+1},& \text{if }x\ge 0,\\ 0,& \text{otherwise}\end{cases}$$I want to prove that it is right-continuous and non-decreasing...."
host: math.stackexchange.com
image: https://cdn.sstatic.net/Sites/math/Img/apple-touch-icon@2.png?v=4ec1df2e49b1

This causes a parse error: