[next-mdx-remote] error compiling MDX: Unexpected character `!` (U+0021) before name, expected a character that can start a name, such as a letter, `$`, or `_` (note: to create a comment in MDX, use `{/* text */}`) 1 | <header> 2 | > 3 | <!-- | ^ 4 | <<< Author notes: Course header >>> 5 | Include a 1280×640 image, course title in sentence case, and a concise description in emphasis. More information: https://mdxjs.com/docs/troubleshooting-mdx