Add Language Model Decoder

Closes #142 (closed)

Taking over from !222 (closed)

dan/ocr/decoder.py

@@ -495,7 +495,7 @@ class CTCLanguageDecoder:
         }
         self.index_to_token = {i: token for token, i in self.tokens_to_index.items()}
         self.blank_token_id = self.tokens_to_index[self.mapping.ctc.encoded]
-        
+
         # Torchaudio's decoder
         # https://pytorch.org/audio/master/generated/torchaudio.models.decoder.ctc_decoder.html
         self.decoder = ctc_decoder(