Docs: Clearify if npm packages can be used

[MentalGear]

This looks really sweet, but most real world apps need to use npm packages. Can these be used with typescript support?

[arctic-hen7]

Perseus is built on top of Sycamore and wasm-bindgen, so absolutely! Honestly, you can usually find what you need in the Rust ecosystem, and most crates run on Wasm these days, so personally I've very rarely needed npm packages. That said, you can absolutely do JS interop through wasm-bindgen, see their docs for details.