Miscelaneous docs updates and fixes. (#1249)

Update references to things in CraneStation which have moved, WASI documentation
which has moved to the WASI repo, and fix a few typos.

crates/wasi-common/README.md

@@ -42,7 +42,7 @@ We expect these to be implemented when network access is standardised.
 We also currently do not support the `proc_raise` hostcall, as it is expected to
 be dropped entirely from WASI.
 
-[WASI API]: https://github.com/bytecodealliance/wasmtime/blob/master/docs/WASI-api.md
+[WASI API]: https://github.com/WebAssembly/WASI/blob/master/phases/snapshot/docs.md
 
 ### Windows
 In our Windows implementation, we currently support the minimal subset of [WASI API]

crates/wasi-common/src/old/snapshot_0/sys/unix/hostcalls_impl/mod.rs

@@ -1,5 +1,5 @@
 //! Unix-specific hostcalls that implement
-//! [WASI](https://github.com/bytecodealliance/wasmtime-wasi/blob/wasi/docs/WASI-overview.md).
+//! [WASI](https://github.com/WebAssembly/WASI).
 mod fs;
 pub(crate) mod fs_helpers;
 mod misc;

crates/wasi-common/src/old/snapshot_0/sys/windows/hostcalls_impl/mod.rs

@@ -1,5 +1,5 @@
 //! Windows-specific hostcalls that implement
-//! [WASI](https://github.com/bytecodealliance/wasmtime-wasi/blob/wasi/docs/WASI-overview.md).
+//! [WASI](https://github.com/WebAssembly/WASI).
 mod fs;
 pub(crate) mod fs_helpers;
 mod misc;

crates/wasi-common/src/sys/unix/hostcalls_impl/mod.rs

@@ -1,5 +1,5 @@
 //! Unix-specific hostcalls that implement
-//! [WASI](https://github.com/bytecodealliance/wasmtime-wasi/blob/wasi/docs/WASI-overview.md).
+//! [WASI](https://github.com/WebAssembly/WASI).
 mod fs;
 pub(crate) mod fs_helpers;
 mod misc;

crates/wasi-common/src/sys/windows/hostcalls_impl/mod.rs

@@ -1,5 +1,5 @@
 //! Windows-specific hostcalls that implement
-//! [WASI](https://github.com/bytecodealliance/wasmtime-wasi/blob/wasi/docs/WASI-overview.md).
+//! [WASI](https://github.com/WebAssembly/WASI).
 mod fs;
 pub(crate) mod fs_helpers;
 mod misc;