Show an initial empty keymap (#14609)

Release Notes:

- Added default content for the user keymap file.

crates/settings/src/settings.rs

@@ -54,6 +54,10 @@ pub fn initial_local_settings_content() -> Cow<'static, str> {
     asset_str::<SettingsAssets>("settings/initial_local_settings.json")
 }
 
+pub fn initial_keymap_content() -> Cow<'static, str> {
+    asset_str::<SettingsAssets>("keymaps/initial.json")
+}
+
 pub fn initial_tasks_content() -> Cow<'static, str> {
     asset_str::<SettingsAssets>("settings/initial_tasks.json")
 }