message: doc(api) Improve the crate documentation.
diff: -#![doc(
  - html_logo_url = "https://github.com/wasmerio.png?size=200",
  - html_favicon_url = "https://wasmer.io/images/icons/favicon-32x32.png"
  -)]
  -#![deny(
  - missing_docs,
  - trivial_numeric_casts,
  - unused_extern_crates,
  - broken_intra_doc_links
  -)]
  -#![warn(unused_import_braces)]
  -#![cfg_attr(
  - feature = "cargo-clippy",
  - allow(clippy::new_without_default, clippy::vtable_address_comparisons)
  -)]
  -#![cfg_attr(
  - feature = "cargo-clippy",
  - warn(
  - clippy::float_arithmetic,
  - clippy::mut_mut,
  - clippy::nonminimal_bool,
  - clippy::map_unwrap_or,
  - clippy::print_stdout,
  - clippy::unicode_not_nfc,
  - clippy::use_self
  - )
  -)]
  -
  -//! This crate contains the `wasmer-js` API. The `wasmer-js` API facilitates the efficient,
  -//! sandboxed execution of [WebAssembly (Wasm)][wasm] modules, leveraging on the same
  -//! API as the `wasmer` crate, but targeting Javascript.
  -//!
  -//! This crate uses the same WebAssembly engine as the Javascript VM where it's used.
  -//!
  -//! Here's an example of the `wasmer-js` API in action:
  -//! ```
  -//! #[wasm_bindgen]
  -//! pub extern fn do_add_one_in_wasmer() -> i32 {
  -//! let module_wat = r#"
  -//! (module
  -//! (type $t0 (func (param i32) (result i32)))
  -//! (func $add_one (export "add_one") (type $t0) (param $p0 i32) (result i32)
  -//! get_local $p0
  -//! i32.const 1
  -//! i32.add))
  -//! "#;
  -//! let store = Store::default();
  -//! let module = Module::new(&store, &module_wat).unwrap();
  -//! // The module doesn't import anything, so we create an empty import object.
  -//! let import_object = imports! {};
  -//! let instance = Instance::new(&module, &import_object).unwrap();
  -//! let add_one = instance.exports.get_function("add_one").unwrap();
  -//! let result = add_one.call(&[Value::I32(42)]).unwrap();
  -//! assert_eq!(result[0], Value::I32(43));
  -//! result[0].unwrap_i32()
  -//! }
  -//! ```
  -//!
  -//! For more examples of using the `wasmer` API, check out the
  -//! [wasmer examples][wasmer-examples].
  -
  #[cfg(all(feature = "std", feature = "core"))]
  compile_error!(
  "The `std` and `core` features are both enabled, which is an error. Please enable only once."
  