Merge pull request #7 from open-mmlab/master

Update readme

README.md

-# mm-det
-Open MMLab Detection Toolbox
+# mm-detection
+Open-MMLab Detection Toolbox
+
+**Note:** 
+
+We are still working on organizing the codebase. This toolbox will be formally released by the end of September. Stay tuned!
+
+---
+
+## Major Features
+
+- **Modular Design**
+
+  One can easily construct a customized object detection framework by combining different components. 
+  
+- **Support of multiple frameworks out of box**
+
+  The toolbox directly supports popular detection frameworks, *e.g.* Faster RCNN, Mask RCNN, and R-FCN, etc.
+  
+- **State of the art**
+
+  This was the codebase of the *MMDet* team, who won the [COCO Detection 2018 challenge](http://cocodataset.org/#detection-leaderboard). 
+