Use design's omnibar placeholder copy

The design's TopBar.url placeholder reads `Search ELY or type a
command…`. We were shipping `Search or enter address`, the generic
URL-bar string from when the omnibar didn't yet host commands.

Match the design copy so the empty-state on `ely://new-tab` matches
home.jsx and command.jsx exactly.

crates/ely_app/src/shell/mod.rs

@@ -109,8 +109,9 @@ impl ElyShell {
         window: &mut Window,
         cx: &mut Context<Self>,
     ) -> Self {
-        let command_input =
-            cx.new(|cx| InputState::new(window, cx).placeholder("Search or enter address"));
+        let command_input = cx.new(|cx| {
+            InputState::new(window, cx).placeholder("Search ELY or type a command…")
+        });
         let plugin_search_input =
             cx.new(|cx| InputState::new(window, cx).placeholder("Search plugins…"));
         let translucency_slider = cx.new(|_cx| {