configuring component dependency default registry

[michelleN]

From component dependencies doc: `

registry	Optional	The registry that hosts the package. If omitted, this defaults to your system default registry.
`

How does default registry get set and how can I find out what the default registry is? cc/ @fibonacci1729

[fibonacci1729]

@itowlson is system default registry here referring to whatever is in - waves hands - wkg.toml?

[itowlson]

bursts into tears

[itowlson]

It is, AS ANY FULE KNO, ~/.config/wasm-pkg/config.toml, and I think the wkg tool sets this up, but nothing else does. My experience is that 1. it creates confusion because nobody has this file and 2. it makes stuff unportable because you and I might have different default registries.

We should probably either:

1. Create the file if it doesn't exist, with the default being Spin's favourite registry
2. If the file doesn't exist, default the registry at the code level to Spin's favourite registry
3. Make specifying the registry mandatory (and double check that everything still works in the absence of the wkg file, which I recall Kate having some problems with)

3 would presumably be a breaking change though.

[itowlson]

Actually I don't even know if that's the current config path, it's what I set up on my machine back when wkg was called wasm-pkg-tools or something, so the recommended path may be something else now, I have not been following the whole drama.