examples/seq2seq supports translation (#5202)

examples/seq2seq/finetune_t5.sh

@@ -0,0 +1,18 @@
+export OUTPUT_DIR_NAME=t5
+export CURRENT_DIR=${PWD}
+export OUTPUT_DIR=${CURRENT_DIR}/${OUTPUT_DIR_NAME}
+
+# Make output directory if it doesn't exist
+mkdir -p $OUTPUT_DIR
+
+# Add parent directory to python path to access lightning_base.py
+export PYTHONPATH="../":"${PYTHONPATH}"
+
+python finetune.py \
+--data_dir=./cnn-dailymail/cnn_dm \
+--model_name_or_path=t5-large \
+--learning_rate=3e-5 \
+--train_batch_size=4 \
+--eval_batch_size=4 \
+--output_dir=$OUTPUT_DIR \
+--do_train  $@