Writes the picture of the chooser's rules to docs/chooser-rules.svg: cargo run -p whiskers-chooser --example draw. A test fails when the checked-in picture is not what this writes, so the picture is the network that runs.

5#[path = "../tests/common/mod.rs"]
6mod common;
8fn main() {
9    let path = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("docs/chooser-rules.svg");
10    std::fs::write(&path, common::rules_svg()).expect("the picture can be written");
11    println!("wrote {}", path.display());
12}