Slm syntax highliting breaks at nested quotes

[mstssk]

• I have searched through existing issues
• I have read through docs
• I have read FAQ

Info

• Platform: macOS
• Vetur version: 0.16.2
• VS Code version: 1.31.1

Problem

I wrote v-if attribute with nested double quotes and single quotes in Slm template.
Slm syntax highliting breaks at nested quotes.

Reproducible Case

Reproduction code.

<template lang="slm">
  div v-if="state === 'initialized'"
    slot
</template>
<script>
export default {
  data: {
    state: "foobar"
  }
};
</script>
<style>
</style>

[octref]

This is because I used text.pug.slm for embedded SLM, but it should be text.jade.slm with https://marketplace.visualstudio.com/items?itemName=mrmlnc.vscode-slm.