Wrapping Markdown in a <div> breaks syntax highlighting in editor

[RobertBeekman]

Describe the bug
If you put your markdown inside a div, it renders correctly on the page and in the preview, but the editor's syntax highlighting stops working

To Reproduce
Steps to reproduce the behavior:

1. Create a Markdown page
2. Wrap the Markdown in <div> and </div>
3. Watch syntax highlighting dissapear

Expected behavior
Syntax highlighting inside the div should remain functional, or Markdown inside the div shouldn't be rendered on the preview and the resulting page either (less desirable I'd imagine).

Screenshots
Syntax highlighting works without the divs:

Wrapping divs breaks the syntax highlighting:

Host Info (please complete the following information):

• OS: Windows_NT (win32) 10.0.18362 ia32
• Wiki.js version: 2.0.0-rc.17
• Database engine: postgres 11.3