Add optional file logging and fix board offsets

Introduce --log CLI flag to enable logging to
war_in_tunnels.log via simplelog.

src/logs.rs

@@ -0,0 +1,11 @@
+use simplelog::{Config, LevelFilter, WriteLogger};
+use std::fs::File;
+
+pub fn init_logger() {
+    WriteLogger::init(
+        LevelFilter::Info,
+        Config::default(),
+        File::create("war_in_tunnels.log").expect("Failed to create log file"),
+    )
+    .expect("Failed to initialize logger");
+}