Here's a Python async function. What would the Elixir version be like?

Probably something like:

path
|> Path.join("**/*.md")
|> Path.wildcard()
|> Task.async_stream(&repair_file_in_place/1)
|> Stream.run()

Concurrency can be limited using options passed to async_stream. Docs: Task — Elixir v1.20.2

(Note: untested and possibly not optimal, but this is the first that came to mind!)