Would PR for brotli support be entertained?

Within the compression features of iostreams, I'm considering adding support for [brotli](https://github.com/google/brotli) compression. It's a very common compression format, particularly on the web. It supports streaming with various window sizes, making it an optimal candidate for iostreams.

Before I invest any time into this support, I'd like to know if the format is of interest, of if there are known characteristics of brotli that have previously excluded it from considering (other than effort to support).

The issue concerns Boost.Iostreams compression features and Google's brotli library. First review the existing compression support and brotli's streaming interface, then confirm whether maintainers want the feature before defining an implementation. Done would require an agreed scope and maintainer approval, followed by implementation and tests.

Written by the indexing model from the issue text.