chore(player): add comments to up/down kb events

src/video/components/actions/KeyboardShortcutsAction.tsx

@@ -63,10 +63,12 @@ export function KeyboardShortcutsAction() {
           toggleVolume();
           break;
 
+        // Decrease volume
         case "arrowdown":
           controls.setVolume(Math.max(mediaPlaying.volume - 0.1, 0));
           break;
 
+        // Increase volume
         case "arrowup":
           controls.setVolume(Math.min(mediaPlaying.volume + 0.1, 1));
           break;