Preparation for sharing

- rustfmt
- clippy
- comments
- README

src/cli.rs

@@ -1,19 +1,22 @@
-use std::{fmt::Display, io::{stdin, BufRead, stdout, Write}};
+use std::fmt::Display;
+use std::io::{stdin, stdout, BufRead, Write};
 
 pub fn prompt<T: Display, E: Display>(
   prompt: &str,
   default: T,
-  mut try_cast: impl FnMut(String) -> Result<T, E>
+  mut try_cast: impl FnMut(String) -> Result<T, E>,
 ) -> T {
   loop {
     print!("{prompt} ({default}): ");
     stdout().lock().flush().unwrap();
     let mut input = String::with_capacity(100);
     stdin().lock().read_line(&mut input).unwrap();
-    if input.is_empty() {return default}
+    if input.is_empty() {
+      return default;
+    }
     match try_cast(input) {
       Ok(t) => return t,
-      Err(e) => println!("Error: {e}")
+      Err(e) => println!("Error: {e}"),
     }
   }
-}
+}