Add comment to top of day 5 and 6

day_05/src/main.rs

@@ -1,3 +1,7 @@
+// https://adventofcode.com/2024/day/5
+//
+// Run command: cargo run ./input.txt
+
 use std::{
     collections::{HashMap, HashSet},
     env,

day_06/src/main.rs

@@ -1,3 +1,7 @@
+// https://adventofcode.com/2024/day/6
+//
+// Run command: cargo run ./input.txt
+
 use std::{
     env,
     error::Error,