Update a poster

[SThompson05]

• render a JSON representation of all records of the requested resource
• always return an array of data, even if one or zero resources are found
• follow this pattern: GET /api/v1/posters

{
  "data": [
    {
      "id": "1",
      "type": "poster",
      "attributes": {
        "name": "FAILURE",
        "description": "Why bother trying? It's probably not worth it.",
        "price": 68.00,
        "year": 2019,
        "vintage": true,
        "img_url": "https://images.unsplash.com/photo-1620401537439-98e94c004b0d"
      }
    },
    {
      "id": "2",
      "type": "poster",
      "attributes": {
        "name": "REGRET",
        "description": "Hard work rarely pays off.",
        "price": 89.00,
        "year": 2018,
        "vintage": true,
        "img_url":  "https://plus.unsplash.com/premium_photo-1661293818249-fddbddf07a5d",
      }
    },
    {
      "id": "3",
      "type": "poster",
      "attributes": {
        "name": "MEDIOCRITY",
        "description": "Dreams are just that—dreams.",
        "price": 127.00,
        "year": 2021,
        "vintage": false,
        "img_url": "https://images.unsplash.com/photo-1551993005-75c4131b6bd8",
      }
    }
  ]
}