docs: Theming and Integrate Custom Components pages are broken

[lucivpav]

Bug Report

There is a bunch of React errors when trying to render one of the following sections:

• Theming
• Integrate Custom Components

The errors prevent any content to be rendered, resulting in a blank page. The issue is present on current master branch: f755bfc

Steps

1. Run the docs site locally.
2. Navigate to http://localhost:port/integrate-custom-components or http://localhost:port/theming
3. Inspect the website to see the errors.
4. No content is rendered.

Expected Result

No errors when navigating to the aforementioned sections. Their content is rendered properly.

Actual Result

React errors when navigation to the aforementioned sections. No rendered content - blank screen.

Version

0.34.0 f755bfc