editor: Show hints for using AI features on empty lines (#20824)

Co-Authored-by: Thorsten <thorsten@zed.dev>
Co-Authored-by: Antonio <antonio@zed.dev>

Screenshot:

![screenshot-2024-11-18-17 11
08@2x](https://github.com/user-attachments/assets/610fd7db-7476-4b9b-9465-a3d55df12340)

TODO:
- [x] docs

Release Notes:

- Added inline hints that guide users on how to invoke the inline
assistant and open the assistant panel. (These hints can be disabled by
setting `{"assistant": {"show_hints": false}}`.)

---------

Co-authored-by: Thorsten <thorsten@zed.dev>
Co-authored-by: Antonio <antonio@zed.dev>
Co-authored-by: Thorsten Ball <mrnugget@gmail.com>

crates/recent_projects/src/recent_projects.rs

@@ -185,13 +185,13 @@ impl PickerDelegate for RecentProjectsDelegate {
     fn placeholder_text(&self, cx: &mut WindowContext) -> Arc<str> {
         let (create_window, reuse_window) = if self.create_new_window {
             (
-                cx.keystroke_text_for(&menu::Confirm),
-                cx.keystroke_text_for(&menu::SecondaryConfirm),
+                cx.keystroke_text_for_action(&menu::Confirm),
+                cx.keystroke_text_for_action(&menu::SecondaryConfirm),
             )
         } else {
             (
-                cx.keystroke_text_for(&menu::SecondaryConfirm),
-                cx.keystroke_text_for(&menu::Confirm),
+                cx.keystroke_text_for_action(&menu::SecondaryConfirm),
+                cx.keystroke_text_for_action(&menu::Confirm),
             )
         };
         Arc::from(format!(