Adding example for list itemm

docs/examples/widgets/list_view.css

@@ -0,0 +1,13 @@
+Screen {
+    align: center middle;
+}
+
+ListView {
+    width: 30;
+    height: auto;
+    margin: 2 2;
+}
+
+Label {
+    padding: 1 2;
+}

docs/examples/widgets/list_view.py

@@ -0,0 +1,17 @@
+from textual.app import App, ComposeResult
+from textual.widgets import ListView, ListItem, Label, Footer
+
+
+class ListViewExample(App):
+    def compose(self) -> ComposeResult:
+        yield ListView(
+            ListItem(Label("One")),
+            ListItem(Label("Two")),
+            ListItem(Label("Three")),
+        )
+        yield Footer()
+
+
+app = ListViewExample(css_path="list_view.css")
+if __name__ == "__main__":
+    app.run()

src/textual/widgets/_list_item.py

@@ -15,7 +15,10 @@ class ListItem(Widget, can_focus=False):
     ListItem > Widget :hover {
         background: $boost;
     }
-    ListItem.--highlight {
+    ListView ListItem.--highlight {
+        background: $accent 50%;
+    }
+    ListView:focus ListItem.--highlight {
         background: $accent;
     }
     ListItem > Widget {