message: Add deprecation warning for mouse URL config
  Fixes
diff: @@ -7,6 +7,8 @@ pub struct Mouse {
  pub double_click: ClickHandler,
  pub triple_click: ClickHandler,
  pub hide_when_typing: bool,
  + #[config(deprecated = "use `hints` section instead")]
  + pub url: Option<serde_yaml::Value>,
  }
  #[derive(ConfigDeserialize, Clone, Debug, PartialEq, Eq)]
  