[Docs] Headings in sidebar for API page displayed incorrectly

[Alex-Sokolov]

Headings with code blocks for <router-link> and <router-view> in sidebar displayed incorrectly for API page (https://router.vuejs.org/api/)

[vue-bot]

Hello, your issue has been closed because it does not conform to our issue requirements. In order to ensure every issue provides the necessary information for us to investigate, we require the use of the Issue Helper when creating new issues. Thank you!

[posva]

Thanks, opened vuejs/vuepress#645