💡 Feature description

Right now wasm-pack allows passing arguments to cargo build, but doesn't do the same for wasm-bindgen. I feel like this should be a pretty important feature to have. In my case, I want to use --weak-refs flag with wasm-bindgen, and at the moment I see no way to use this feature while using wasm-pack.

For the syntax, we could add a flag:

# Like this:
wasm-pack --wbg-arg --weak-refs --wbg-arg --reference-types
# Or this:
wasm-pack --wbg-args '--weak-refs --reference-types'

The only problem I see with this syntax is it's different from the syntax for passing arguments to cargo, which is done with the -- flag. That's a bit unfortunate, but ¯\_(ツ)_/¯.

So, what do people think?