Add documentation

Extensive doc comments were added to keybindings, CLI options, logging,
and
widget modules. The `count_largest_group` function was introduced to
compute
the largest group size among actions. CLI validation for
`skill_points_limit`
was broadened to a 90‑690 range. Imports and signatures for `Display`
were
adjusted accordingly.

src/logs.rs

@@ -1,6 +1,32 @@
 use simplelog::{Config, LevelFilter, WriteLogger};
 use std::fs::File;
 
+/// Initializes the global logger for the application.
+///
+/// This function creates (or truncates) a file called `war_in_tunnels.log`
+/// in the current working directory and configures a `simplelog::WriteLogger`
+/// to write log messages with a minimum level of `Info`.
+///
+/// # Panics
+///
+/// - If the log file cannot be created (e.g., due to permission issues).
+/// - If the logger cannot be initialized (which would indicate an internal
+///   error in the `simplelog` crate).
+///
+/// Call this once, preferably at the very beginning of `main()`, before any
+/// logging macros are used.
+///
+/// # Example
+///
+/// ```
+/// use war_in_tunnels::logs::init_logger;
+/// use log::info;
+///
+/// fn main() {
+///     init_logger();
+///     info!("Application started");
+/// }
+/// ```
 pub fn init_logger() {
     WriteLogger::init(
         LevelFilter::Info,