Add TypeScript types to documentation using TwoSlash

[jsudelko]

TwoSlash allows you to add types to your code block markup. For a TypeScript-focused library it would be a godsend. Sometimes I have to switch back and forth between VS Code and docs copying over documentation examples in order to understand what something means or the expected type output. It would he handy if I could simply hover to see the actual TypeScript types.

See Rollup as an example of TwoSlash in the wild. Hover over the JavaScript code snippet.

[fabian-hiller]

Thank you for sharing. Feel free to create a PR and implement it.