update docs

Author: L1aoXingyu

demo/README.md

@@ -2,9 +2,10 @@
 
 We provide a command line tool to run a simple demo of builtin models.
 
-You can run this command to get cosine similarites between different images 
+You can run this command to get cosine similarites between different images
 
 ```bash
-cd demo/
-sh run_demo.sh
-```
+python demo/visualize_result.py --config-file logs/dukemtmc/mgn_R50-ibn/config.yaml \
+--parallel --vis-label --dataset-name DukeMTMC --output logs/mgn_duke_vis \
+--opts MODEL.WEIGHTS logs/dukemtmc/mgn_R50-ibn/model_final.pth
+```