* docs: add documentation for iterating over channels
* fix: deduplicate protomux instances for the same stream
creating multiple channels on multiple muxers for the same stream closes
channels accidently see
[here](https://gist.github.com/Nazeh/a3f1d24b597913303afcb6c568f4b042)
* fix: deduplicate muxers on the same stream
opening multiple channels on multiple muxers causes channels to either
close or reset, see
[here](https://gist.github.com/Nazeh/a3f1d24b597913303afcb6c568f4b042)
* use userData