README example does not compile

[gagath]

The example in the README fails to compile with the following errors and warnings:

warning: unused import: `std::fs`
  --> src/main.rs:15:5
   |
15 | use std::fs;
   |     ^^^^^^^
   |
   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default

warning: unused import: `std::path::Path`
  --> src/main.rs:16:5
   |
16 | use std::path::Path;
   |     ^^^^^^^^^^^^^^^

error[E0433]: cannot find module or crate `byteorder` in this scope
  --> src/main.rs:25:31
   |
25 | ...Str, U32<byteorder::NativeEndian>> = env.create_database(&mut wtxn, None)?;
   |             ^^^^^^^^^ use of unresolved module or unlinked crate `byteorder`
   |
   = help: if you wanted to use a crate named `byteorder`, use `cargo add byteorder` to add it to your `Cargo.toml`