This is an example of how to set up TextMate grammars for Monaco Editor in a simple Next.js app.
Copy any relevant language grammars found here.
https://codesandbox.io/post/introducing-themes#how-it-works
https://github.com/NeekSandhu/monaco-textmate
microsoft/monaco-editor-webpack-plugin#141 (comment)
https://stackoverflow.com/a/65967072/1461204
https://github.com/ChristopherHButler/vscode-themes-in-monaco