* Add support for the experimental wasi-crypto APIs
The sole purpose of the implementation is to allow bindings and
application developers to test the proposed APIs.
Rust and AssemblyScript bindings are also available as examples.
Like `wasi-nn`, it is currently disabled by default, and requires
the `wasi-crypto` feature flag to be compiled in.
* Rename the wasi-crypto/spec submodule
* Add a path dependency into the submodule for wasi-crypto
* Tell the publish script to vendor wasi-crypto
