refactor: create library with simple entrypoint in main

Create a library entrypoint 'src/lib.rs' and refactor binary entrypoint
'src/main.rs' accordingly.

src/lib.rs

@@ -0,0 +1,10 @@
+#![allow(unused)]
+
+pub mod cli;
+pub mod scripts;
+
+// NOTE: stolen from https://docs.rs/debug_print/latest/debug_print/
+#[macro_export]
+macro_rules! debug_println {
+    ($($arg:tt)*) => (if ::std::cfg!(debug_assertions) { ::std::println!($($arg)*); })
+}

src/main.rs

@@ -1,11 +1,7 @@
-#![allow(unused)]
+use ahab::{cli, scripts};
-
-mod cli;
-mod scripts;
 
 use anyhow::Result;
 use clap::Parser;
-use std::env;
 
 fn main() -> Result<()> {
     // always load dotenv on start