Update README.md

Update model card with Checkpoint 2 training metrics (16M tokens, EV=0.831, loss=0.586)

Checkpoint README: 16,001,024 tokens

Colab T4 checkpoint: 16,001,024 tokens

Colab T4 checkpoint: 16,001,024 tokens

Colab T4 checkpoint: 16,001,024 tokens

Checkpoint README: 14,003,200 tokens

Colab T4 checkpoint: 14,003,200 tokens

Colab T4 checkpoint: 14,003,200 tokens

Colab T4 checkpoint: 14,003,200 tokens

Checkpoint README: 12,002,304 tokens

Colab T4 checkpoint: 12,002,304 tokens

Colab T4 checkpoint: 12,002,304 tokens

Colab T4 checkpoint: 12,002,304 tokens

Checkpoint README: 10,001,408 tokens

Colab T4 checkpoint: 10,001,408 tokens

Colab T4 checkpoint: 10,001,408 tokens

Colab T4 checkpoint: 10,001,408 tokens

Checkpoint README: 8,000,512 tokens

Colab T4 checkpoint: 8,000,512 tokens

Colab T4 checkpoint: 8,000,512 tokens

Colab T4 checkpoint: 8,000,512 tokens

Checkpoint README: 6,002,688 tokens

Colab T4 checkpoint: 6,002,688 tokens

Colab T4 checkpoint: 6,002,688 tokens

Colab T4 checkpoint: 6,002,688 tokens

Checkpoint README: 4,001,792 tokens

Colab T4 checkpoint: 4,001,792 tokens

Colab T4 checkpoint: 4,001,792 tokens

Colab T4 checkpoint: 4,001,792 tokens

Checkpoint README: 2,000,896 tokens

Colab T4 checkpoint: 2,000,896 tokens

Colab T4 checkpoint: 2,000,896 tokens

Colab T4 checkpoint: 2,000,896 tokens

Colab T4 checkpoint: 2,000,896 tokens

initial commit