!13125 modified shell in yolov4 network

From: @shuzigood
Reviewed-by: 
Signed-off-by:

model_zoo/official/cv/yolov4/README.md

@@ -46,15 +46,14 @@ Annotation support: [MS COCO] or annotation as the same format as MS COCO
                 ├── annotations
                 │   ├─ train.json
                 │   └─ val.json
-                ├─  ├─train
+                ├─train
                 │   ├─picture1.jpg
                 │   ├─ ...
                 │   └─picturen.jpg
-                    └─ val
+                ├─ val
                     ├─picture1.jpg
                     ├─ ...
                     └─picturen.jpg
-                
     ```
 
 we suggest user to use MS COCO dataset to experience our model,
@@ -409,6 +408,7 @@ Current batch_Size can only be set to 1. The precision calculation process needs
 # Ascend310 inference
 sh run_infer_310.sh [MINDIR_PATH] [DATA_PATH] [DEVICE_ID] [ANN_FILE]
 ```
+
 `DEVICE_ID` is optional, default value is 0.
 
 ### result

model_zoo/official/cv/yolov4/scripts/run_distribute_train.sh

@@ -56,6 +56,7 @@ fi
 export DEVICE_NUM=8
 export RANK_SIZE=8
 export RANK_TABLE_FILE=$RANK_TABLE_FILE
+export MINDSPORE_HCCL_CONFIG_PATH=$RANK_TABLE_FILE
 
 for((i=0; i<${DEVICE_NUM}; i++))
 do