Add print-tree command.

src/main.rs

@@ -173,6 +173,10 @@ struct Args {
     /// Path to wiki repository
     wiki_path: Option<String>,
 
+    /// Print a tree of the wiki contents.
+    #[arg(long)]
+    print_tree: bool,
+    
     /// Render the wiki to a static website
     #[arg(long)]
     render_to: Option<String>,
@@ -205,7 +209,11 @@ async fn main() {
 
     if let Some(wiki_path) = args.wiki_path {
         let historian = Historian::new(wiki_path);
-        print_tree(&historian, &historian.resolve_to_page("").unwrap(), "*");
+        
+        if args.print_tree {
+            print_tree(&historian, &historian.resolve_to_page("").unwrap(), "*");
+            return;
+        }
 
         let renderer = if let Some(template_path) = args.template_path {
             PageRenderer::with_template_path(&template_path)