Add zstd module

[marvinruder]

Feature Overview

I would like to request that a module for zstd compression be added to this repository. An implementation is available from https://github.com/tokers/zstd-nginx-module.

Alternatives Considered

No response

Additional Context

No response

[thresheek]

Thanks for the feature request @marvinruder!

Let's use this issue to track interest for this module, and if it proves to have a popular demand, we'll consider including it to our suite.

[ptognotti]

Very interested in having this added :)

[viravera]

I'm interested in this.