Show warning when multiple game entries point to same file(s) about ludusavi HOT 4 CLOSED

$ ludusavi backup --preview 'A Custom Game' 'A Custom Game 2'
A Custom Game [3 B] [DUPLICATES]:
  - [DUPLICATED] C:/tmp/ludusavi/file1.txt
  - C:/tmp/ludusavi/file2.txt
  - [DUPLICATED] HKEY_CURRENT_USER/Software/Ludusavi
A Custom Game 2 [1 B] [DUPLICATES]:
  - [DUPLICATED] C:/tmp/ludusavi/file1.txt
  - [DUPLICATED] HKEY_CURRENT_USER/Software/Ludusavi

Overall:
  Games: 2
  Size: 4 B
  Location: C:/Users/mtken/ludusavi-backup

$ ludusavi backup --preview --api 'A Custom Game' 'A Custom Game 2'
{
  "overall": {
    "totalGames": 2,
    "totalBytes": 4,
    "processedGames": 2,
    "processedBytes": 4
  },
  "games": {
    "A Custom Game": {
      "decision": "Processed",
      "files": {
        "C:/tmp/ludusavi/file1.txt": {
          "bytes": 1,
          "duplicatedBy": [
            "A Custom Game 2"
          ]
        },
        "C:/tmp/ludusavi/file2.txt": {
          "bytes": 2
        }
      },
      "registry": {
        "HKEY_CURRENT_USER/Software/Ludusavi": {
          "duplicatedBy": [
            "A Custom Game 2"
          ]
        }
      }
    },
    "A Custom Game 2": {
      "decision": "Processed",
      "files": {
        "C:/tmp/ludusavi/file1.txt": {
          "bytes": 1,
          "duplicatedBy": [
            "A Custom Game"
          ]
        }
      },
      "registry": {
        "HKEY_CURRENT_USER/Software/Ludusavi": {
          "duplicatedBy": [
            "A Custom Game"
          ]
        }
      }
    }
  }
}