Feat: basic argument parsing.

src/main.rs

@@ -1,3 +1,6 @@
 fn main() {
-    println!("Hello, world!");
+    let pattern = std::env::args().nth(1).expect("no pattern given.");
+    let path = std::env::args().nth(2).expect("no path given.");
+
+    println!("pattern: {:?}, path: {:?}", pattern, path)
 }