// petición POST o PUT para un producto
{
    "tienda_id": "hashcodefd928793",
    "props1":     "blabla",
    "props2":    "blablabla",
    "props3":    "bloodyblaa",
    "comentarios": [
      {
        "comentario_id": 1,
      "category": "adsfasdfasdf",
      "subcategory": "balbalblaa",
      "commentario": "yyyworldddasf",
      },
      {
      "comentario_id": 2,
      "category": "adsfadsft",
      "subcategory": "adadfddd",
       "commentario": "adsfdasdfasdf",
      },
      {
      "comentario_id": 3,
      "category": "dlkfjañdslkf",
      "subcategory": "ñalsdfj",
      "commentario": "añlsdkfja.",
      }
    ]
}