List destination specs

curl --request GET \
  --url https://api.portable.io/v2/destinationspecs \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "name": "<string>",
      "displayName": "<string>",
      "website": "<string>",
      "tagLine": "<string>",
      "lifecycle": "ALPHA"
    }
  ]
}