message: Add `unfocus` method to `pane_grid::State`
diff: @@ -193,6 +193,13 @@ impl<T> State<T> {
  self.internal.focus(pane);
  }
  + /// Unfocuses the current focused [`Pane`].
  + ///
  + /// [`Pane`]: struct.Pane.html
  + pub fn unfocus(&mut self) {
  + self.internal.unfocus();
  + }
  +
  /// Splits the given [`Pane`] into two in the given [`Axis`] and
  /// initializing the new [`Pane`] with the provided internal state.
  ///
  