Well, you can add code blocks with named syntax to Markdown, with the Nostr Markdown flavor. You would just need to design a client that reacted when it encountered a code block like

```wld

This is a code block containing nostr:npub1wamvxt2tr50ghu4fdw47ksadnt0p277nv0vfhplmv0n0z3243zyq26u3l2's awesome new functionality.

```