Update TRAIN.md

Author: jwyang

asset/TRAIN.md

@@ -1,9 +1,14 @@
 ### Installation
 
-First download coco caption_class_similarity and put it in folder coco/annotations:
+First download some meta files needed for COCO and put them in folder coco/annotations:
 ```
 wget https://github.com/microsoft/X-Decoder/releases/download/coco/caption_class_similarity.pth
+wget https://huggingface.co/xdecoder/X-Decoder/blob/main/captions_train2017_filtrefgumdval_filtvlp.json
+wget https://huggingface.co/xdecoder/X-Decoder/blob/main/grounding_train2017_filtrefgumdval_filtvlp.json
+
 mv caption_class_similarity.pth /path/to/coco/annotations/
+mv captions_train2017_filtrefgumdval_filtvlp.json /path/to/coco/annotations/
+mv grounding_train2017_filtrefgumdval_filtvlp.json /path/to/coco/annotations/
 ```
 
 Single GPU