Rename object_detection to PaddleDetection. (#2601)

* Rename object_detection to PaddleDetection
* Small fix for doc

PaddleCV/object_detection/README.md → PaddleCV/PaddleDetection/README.md

-# PaddlePaddle Object Detection
+# PaddleDetection
 
 The goal of PaddleDetection is to provide easy access to a wide range of object
-detection models in both industry and research settings. we design
+detection models in both industry and research settings. We design
 PaddleDetection to be not only performant, production-ready but also highly
 flexible, catering to research needs.
 

PaddleCV/object_detection/docs/CONFIG.md → PaddleCV/PaddleDetection/docs/CONFIG.md

@@ -14,7 +14,7 @@ To avoid the common pitfalls, with automation and static analysis in mind, we pr
 
 # Design
 
-The design utilizes some of Python's reflection mechanism to extract configuration schematics from python class definitions.
+The design utilizes some of Python's reflection mechanism to extract configuration schematics from Python class definitions.
 
 To be specific, it extracts information from class constructor arguments, including names, docstrings, default values, data types (if type hints are available).
 
@@ -158,7 +158,7 @@ LearningRate:
 
 # Requirements
 
-Two python packages are used, both are optional.
+Two Python packages are used, both are optional.
 
 -   [typeguard](https://github.com/agronholm/typeguard) is used for type checking in Python 3.
 -   [docstring\_parser](https://github.com/rr-/docstring_parser) is needed for docstring parsing.