Italian translation

[Xemnas97]

Hey, I love your extension and I want to contribute by translating it into Italian, I never made a pull request so I don't know how it works, I'm really sorry... anyway:

 {
  "extensionName": {
    "message": "Chiudi le schede a destra",
    "description": "Name of the extension."
  },

  "extensionDescription": {
    "message": "Aggiunge una voce al menu contestuale delle schede che chiude tutte le schede a destra di quella selezionata",
    "description": "Description of the extension."
  },

  "contextItemTitle": {
      "message": "Chiu&di le schede a destra",
      "description": "Title of the context menu item."
  }
}