Add new measures, json design?

[pfliu-nlp]

Option 1

{
  sample_level: {
       BLEU: []
       BARTScore: []
       src_len: []

 }

  corpus_level:{
    BLEU:
    BARTScore: 
    src_len:
} 

}

[pfliu-nlp]

Option 2

{
  sample_level: [
       BLEU: 
       BARTScore: 
       src_len:
   ]
  corpus_level:{
    BLEU:
    BARTScore: 
    src_len:
} 

}