There is some weird dependency interaction between pulldown-cmark and
getopts which causes builds to fail with a message about unstable
features if getopts is not explicitly depended on as a dependency of a
dependency (yeah, huh?)
Relicense the project from the standard GPL3 to the Affero version of
the license, requiring source code disclosure for modifications made
on instances of Converse that are serving users over the network.
Adds a Nix build configuration baesd on the default rustPlatform
configuration.
The configuration pins a specific nixpkgs commit (which at the time
was a commit tracking nixpkgs-unstable).