Another functional, literal interpretation of Otel

[rossabaker]

I'm poking around at https://github.com/iand675/hs-opentelemetry, a Haskell library that appears to have similar goals:

• The API very closely mimics the Otel spec, as we have aspired to do
• It's Haskell, so it's purely functional
• Their inSpan and inSpan' are a lot like a Resource[F, Span[F]] with surround and use, respectively.
• They're using a thread-local context. It looks like you're on your own when you fork new threads.

All in all, it looks like they're in a very similar direction to us, and are compatible with "local" semantics.