The Nix package manager is used to build the Rust webassembly part of the project. Do the following:
$ nix-build nix/release.nix -A rust-wasm-preset-converter
This compiles the Rust code to webassembly (.wasm file ending) with additional javascript and typescript wrappers that can be imported from your corresponding web project.
To bundle the webassembly together with the website ready to be served via a webserver do the following:
$ nix-build nix/release.nix -A preset-converter
To build and serve the web application that uses the webassembly library do the following:
$ nix-build nix/release.nix -A http-server
This creates a script that on invocation starts a web-server that is accessible
at http://localhost:8000/index.html
per default.