* Build docs with the nightly toolchain so [foo::bar] links work by default. This is a relatively new feature of rustdoc and I thought it was stabilized at this point but apparently it's not! * Tweak some API docs on `wasmtime::Strategy` * Use `--all` to build all local crate documentation instead of trying to list the number of local crates * Tweak some documentation configuration to avoid warnings generated by Cargo.