Fix errors

model.py

@@ -58,10 +58,10 @@ class Block:
         return self
 
 class Transformer():
-    def __init__(self,vocab_size,embed_size,n_heads,n_blocks,max_len):
+    def __init__(self,vocab_size,embed_size,n_heads,n_blocks,block_size):
         self.tok_embed = nn.Embedding(vocab_size,embed_size)
         self.pos_embed = nn.Embedding(block_size,embed_size)
-        self.pos_idx = Tensor.arange(max_len, requires_grad=False)
+        self.pos_idx = Tensor.arange(block_size, requires_grad=False)
 
         self.blocks = [Block(embed_size,n_heads) for _ in range(n_blocks)]
         self.norm = nn.RMSNorm(embed_size)