Fix app.py syntax and download En-Indic checkpoint for Urdu and Kashmiri

app.py

@@ -1,5 +1,5 @@
 app = Flask(__name__)
-# Model expects /app/checkpoints/fairseq_model/ with model.pt
+# Supports eng_Latn to urd_Arab, kas_Deva, kas_Arab
 model = Model('/app/checkpoints', model_type='fairseq')
 
 @app.route('/translate', methods=['POST'])