MDX = MD (Markdown) + JSX (React)

mdx-js/mdx: JSX in Markdown for ambitious projects

MDX is an authorable format that lets you seamlessly use JSX in your markdown documents. You can import components, like interactive charts or notifications, and export metadata. This makes writing long-form content with components a blast.

import { Chart } from '../components/chart'

# Here’s a chart

The chart is rendered inside our MDX document.

<Chart />

What is MDX - YouTube

Using Expo in Gatsby