chore: add document for actions

crates/ui/src/actions.rs

@@ -1,6 +1,7 @@
 use gpui::{actions, Action};
 use serde::Deserialize;
 
+/// Define a custom confirm action
 #[derive(Clone, Action, PartialEq, Eq, Deserialize)]
 #[action(namespace = list, no_json)]
 pub struct Confirm {
@@ -8,4 +9,14 @@ pub struct Confirm {
     pub secondary: bool,
 }
 
-actions!(list, [Cancel, SelectPrev, SelectNext]);
+actions!(
+    list,
+    [
+        /// Close current list
+        Cancel,
+        /// Select the next item in lists
+        SelectPrev,
+        /// Select the previous item in list
+        SelectNext
+    ]
+);