also consider accepting tokenizer, so dalle2 forward pass can just be invoked as DALLE2(<prompt string>)

dalle2_pytorch/dalle2_pytorch.py

@@ -180,12 +180,14 @@ class DALLE2(nn.Module):
         *,
         clip,
         prior,
-        decoder
+        decoder,
+        tokenizer = None
     ):
         super().__init__()
         assert isinstance(clip), CLIP
         assert isinstance(prior), DiffusionPrior
         assert isinstance(decoder), Decoder
+        self.tokenizer = tokenizer
 
     @torch.no_grad()
     def forward(