See src/lib-original.rs for Rust PBO entries reader and src/lib.rs with added WASM glue.
Locally just run build.sh, and run some static server to serve docs.
For example with Ruby/Python built-in server you can do following.
./build.sh
ruby -run -e httpd docs/ # if you have Ruby installed
python -m http.server --directory docs 8080 # if you have Python 3 installed
# now open localhost:8080 in browser