feat!: decouple download and scaffold from main package into workspace

Added workspace structure to Cargo.toml. This way we don't need to build
all dependencies for helper binaries. Also changed .cargo/config
accordingly.

utils/scaffold/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "scaffold"
+description.workspace = true
+readme.workspace = true
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+authors.workspace = true
+repository.workspace = true
+
+[dependencies]
+reqwest = { version = "0.11.22", features = ["blocking"] }
+dotenvy = "0.15.6"
+pico-args = "0.5.0"

utils/scaffold/src/main.rs

@@ -0,0 +1,109 @@
+/*
+ * This file contains template code.
+ * There is no need to edit this file unless you want to change template functionality.
+ */
+use std::{
+    fs::{File, OpenOptions},
+    io::Write,
+    process,
+};
+
+const MODULE_TEMPLATE: &str = r#"pub fn part_one(input: &str) -> Option<u32> {
+    None
+}
+pub fn part_two(input: &str) -> Option<u32> {
+    None
+}
+fn main() {
+    let input = &aoc::read_file("inputs", DAY);
+    aoc::solve!(1, part_one, input);
+    aoc::solve!(2, part_two, input);
+}
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_part_one() {
+        let input = aoc::read_file("examples", DAY);
+        assert_eq!(part_one(&input), None);
+    }
+    #[test]
+    fn test_part_two() {
+        let input = aoc::read_file("examples", DAY);
+        assert_eq!(part_two(&input), None);
+    }
+}
+"#;
+
+pub fn parse_args() -> Result<u8, pico_args::Error> {
+    let mut args = pico_args::Arguments::from_env();
+    args.free_from_str()
+}
+
+fn safe_create_file(path: &str) -> Result<File, std::io::Error> {
+    OpenOptions::new().write(true).create_new(true).open(path)
+}
+
+fn create_file(path: &str) -> Result<File, std::io::Error> {
+    OpenOptions::new().write(true).create(true).open(path)
+}
+
+fn main() {
+    let day = match parse_args() {
+        Ok(day) => day,
+        Err(_) => {
+            eprintln!("Need to specify a day (as integer). example: `cargo scaffold 7`");
+            process::exit(1);
+        }
+    };
+
+    let day_padded = format!("{day:02}");
+
+    let input_path = format!("src/inputs/{day_padded}.txt");
+    let example_path = format!("src/examples/{day_padded}.txt");
+    let module_path = format!("src/bin/{day_padded}.rs");
+
+    let mut file = match safe_create_file(&module_path) {
+        Ok(file) => file,
+        Err(e) => {
+            eprintln!("Failed to create module file: {e}");
+            process::exit(1);
+        }
+    };
+
+    match file.write_all(MODULE_TEMPLATE.replace("DAY", &day.to_string()).as_bytes()) {
+        Ok(_) => {
+            println!("Created module file \"{}\"", &module_path);
+        }
+        Err(e) => {
+            eprintln!("Failed to write module contents: {e}");
+            process::exit(1);
+        }
+    }
+
+    match create_file(&input_path) {
+        Ok(_) => {
+            println!("Created empty input file \"{}\"", &input_path);
+        }
+        Err(e) => {
+            eprintln!("Failed to create input file: {e}");
+            process::exit(1);
+        }
+    }
+
+    match create_file(&example_path) {
+        Ok(_) => {
+            println!("Created empty example file \"{}\"", &example_path);
+        }
+        Err(e) => {
+            eprintln!("Failed to create example file: {e}");
+            process::exit(1);
+        }
+    }
+
+    println!("---");
+    println!(
+        "🎄 Type `cargo solve {}` to run your solution.",
+        &day_padded
+    );
+}