refactor(usage_md): use with_capacity for alias collection

https://claude.ai/code/session_019rqSgsH1KcU2hPSYSUHWhx

Author: claude

src/usage_md.rs

@@ -166,14 +166,18 @@ fn write_option_anchors(out: &mut String, arg: &Arg, primary_long: &str) {
 }
 
 fn collect_option_display_aliases(arg: &Arg) -> Vec<String> {
-    let mut aliases = Vec::<String>::new();
+    let visible_aliases = arg.get_visible_aliases().unwrap_or_default();
+    let visible_short_aliases = arg.get_visible_short_aliases().unwrap_or_default();
+    let mut aliases = Vec::<String>::with_capacity(
+        arg.get_short().is_some() as usize + visible_aliases.len() + visible_short_aliases.len(),
+    );
     if let Some(short) = arg.get_short() {
         aliases.push(format!("-{short}"));
     }
-    for alias in arg.get_visible_aliases().unwrap_or_default() {
+    for alias in visible_aliases {
         aliases.push(format!("--{alias}"));
     }
-    for alias in arg.get_visible_short_aliases().unwrap_or_default() {
+    for alias in visible_short_aliases {
         aliases.push(format!("-{alias}"));
     }
     aliases