The hosting part is, indeed, a technical part but a tool like copyparty can help here:

https://github.com/9001/copyparty/blob/hovudstraum/README.md#markdown-viewer

It runs everywhere, is just a single file you double-click to open and browse from your browser. Makdown files are automatically rendered. You can upload a bunch of files directly, or just send them by mail and put them in a directory served by copyparty