Build script (`build.rs)` needs some documentation
When people come to the codebase, most Rust files have documentation to help the nascent developer to navigate the source. The build script does not.
To reduce the chance that potential first-time-devs run away, we should ensure build.rs
is as well documented. Explain its purpose, link to where its output is consumed inside Subplot's source, and perhaps even link to https://doc.rust-lang.org/cargo/reference/build-scripts.html to explain what a build script is, since new Rust devs probably expect all source to be inside src/
and experienced devs will want to know it's not malicious before they are prepared to run a build.
Edited by Daniel Silverstone