chip8-book VS llvm-project

Not to discourage you, but there's already a CHIP-8 book in progress: https://github.com/aquova/chip8-book

WASM support would be so cool. There are lots of guides online which could help you out. I saw a guide for the chip8 and it didn't even look too difficult, you can check it out here https://github.com/aquova/chip8-book

Recently I've decided to learn low level programming with Rust. I asked for some projects to practice and got recommened to make a Chip8 emulator. That sounded fun so I searched a bit and found this guide that walks you step by step.

I made some emulators in Rust as a learning project during the start of the pandemic, and ran into the exact same issue when I wanted to make a wasm version to run in a browser. Eventually, I was able to figure out how to do it, although I do use the 'wasm-pack' Cargo package to assist with it (I think you can get away without it if you're really motivated, you just need to set up the targets and other elements yourself). Basically you define some Rust API to expose whatever you need from your project, then that and the project get compiled into one .wasm binary and some (surprisingly readable) JavaScript "glue" gets generated which allows for easy inclusion into a web page. It works well for code in the std, but I've had issues with 3rd party packages.

It's focused on emulation development, but I wrote a document that describes the process I followed: https://github.com/aquova/chip8-book/blob/master/src/wasm.md

I followed [this](https://github.com/aquova/chip8-book) book which uses Rust.

This was a topic at CppCon'19 (seems like exactly the same use case as you are describing: teaching!). Take a look at https://www.youtube.com/watch?v=5N4b-rU-OAA. I think it relies on the LLVM fork, so not sure how well it'll work for you, quick web search points to: https://github.com/binji/llvm-project.