Cross platform build

[yanganto]

Currently, SewUp use nix solution can work well on Linux and macOS.

The versions greater than 0.8.2 ofWasmEdge can be built cross-platform, and SewUp use WasmEdge to run test.

Once the Wasmedge upgrated (#24 ), the CI can work on building sewup on windows.

Besides, the cargo.toml should be set with clear supported targets.

[package.metadata.docs.rs]
targets = ["x86_64-unknown-linux-gnu", "x86_64-pc-windows-msvc", "wasm32-unknown-unknown" ... ]