split into library plus binary

Cargo.toml

@@ -3,7 +3,9 @@ name = "thyme"
 version = "0.1.0"
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lib]
+name = "thyme"
+path = "src/lib.rs"
 
 [dependencies]
 png = "*"
@@ -13,3 +15,7 @@ pangocairo = "*"
 serde = { version = "*", features = ["derive"] }
 serde_yaml = "*"
 clap = { version = "*", features = ["derive"] }
+
+[[bin]]
+name = "thyme-from-png"
+path = "tools/from-png/main.rs"

src/lib.rs

@@ -0,0 +1,3 @@
+pub mod data;
+pub mod draw;
+pub mod image;

src/main.rs

@@ -1,13 +1,9 @@
-mod data;
-mod draw;
-mod image;
 mod opts;
 
 use clap::Parser;
-
-use crate::data::{Config, Mapping};
-use crate::draw::Pattern;
-use crate::image::Image;
+use thyme::{data::{Config, Mapping},
+            draw::Pattern,
+            image::Image};
 use crate::opts::Options;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {