Open keymap editor from command palette entry (#40825)

Release Notes:

- Adds footer to the command palette with buttons to add or change the
selected actions keybinding. Both open the keymap editor though the add
button takes you directly to the modal for recording a new keybind.


https://github.com/user-attachments/assets/0ee6b91e-b1dd-4d7f-ad64-cc79689ceeb2

---------

Co-authored-by: Joseph T. Lyons <JosephTLyons@gmail.com>
Co-authored-by: Julia Ryan <juliaryan3.14@gmail.com>
Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

crates/zed_actions/src/lib.rs

@@ -27,6 +27,13 @@ pub struct OpenZedUrl {
     pub url: String,
 }
 
+/// Opens the keymap to either add a keybinding or change an existing one
+#[derive(PartialEq, Clone, Default, Action, JsonSchema, Serialize, Deserialize)]
+#[action(namespace = zed, no_json, no_register)]
+pub struct ChangeKeybinding {
+    pub action: String,
+}
+
 actions!(
     zed,
     [
@@ -232,7 +239,7 @@ pub mod command_palette {
         command_palette,
         [
             /// Toggles the command palette.
-            Toggle
+            Toggle,
         ]
     );
 }