added documentation

src/main.rs

@@ -20,23 +20,32 @@ use crossterm::{
 };
 use ratatui::{backend::CrosstermBackend, Terminal};
 
+/// Helper to automatically determine the output file path based on common naming conventions.
 fn determine_output_path(input: &Path) -> PathBuf {
     let file_name = input.file_name().unwrap_or_default().to_string_lossy();
+    
+    // .env.example -> .env
     if file_name == ".env.example" {
         return input.with_file_name(".env");
     }
+    
+    // docker-compose.yml -> docker-compose.override.yml
     if file_name == "docker-compose.yml" {
         return input.with_file_name("docker-compose.override.yml");
     }
     if file_name == "docker-compose.yaml" {
         return input.with_file_name("docker-compose.override.yaml");
     }
+    
+    // config.example.json -> config.json
     if file_name.ends_with(".example.json") {
         return input.with_file_name(file_name.replace(".example.json", ".json"));
     }
     if file_name.ends_with(".template.json") {
         return input.with_file_name(file_name.replace(".template.json", ".json"));
     }
+    
+    // Fallback: append .out to the extension
     input.with_extension(format!(
         "{}.out",
         input.extension().unwrap_or_default().to_string_lossy()
@@ -44,6 +53,7 @@ fn determine_output_path(input: &Path) -> PathBuf {
 }
 
 fn main() -> Result<(), Box<dyn Error>> {
+    // Parse CLI arguments
     let args = cli::parse();
 
     let input_path = args.input;
@@ -52,13 +62,16 @@ fn main() -> Result<(), Box<dyn Error>> {
         return Ok(());
     }
 
+    // Detect format and select appropriate handler
     let format_type = detect_format(&input_path, args.format);
     let handler = get_handler(format_type);
 
+    // Determine where to save the result
     let output_path = args
         .output
         .unwrap_or_else(|| determine_output_path(&input_path));
 
+    // Initial parsing of the template file
     let mut vars = handler.parse(&input_path).unwrap_or_else(|err| {
         println!("Error parsing input file: {}", err);
         vec![]
@@ -72,22 +85,27 @@ fn main() -> Result<(), Box<dyn Error>> {
         return Ok(());
     }
 
+    // Merge values from an existing output file if it exists
     if let Err(e) = handler.merge(&output_path, &mut vars) {
         println!("Warning: Could not merge existing output file: {}", e);
     }
 
+    // Load user configuration and initialize application state
     let config = load_config();
     let mut app = App::new(vars);
 
+    // Initialize terminal into raw mode and enter alternate screen
     enable_raw_mode()?;
     let mut stdout = io::stdout();
     execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
     let backend = CrosstermBackend::new(stdout);
     let mut terminal = Terminal::new(backend)?;
 
+    // Instantiate the runner and start the application loop
     let mut runner = AppRunner::new(&mut terminal, &mut app, &config, &output_path, handler.as_ref());
     let res = runner.run();
 
+    // Clean up terminal state on exit
     disable_raw_mode()?;
     execute!(
         terminal.backend_mut(),