update setup.py

Author: hpotechius

README.md

@@ -55,15 +55,15 @@ octave:1> gbvs_install.m
 ### Install via PyPI
 ```
 pip install colortransferlib
-pip install colortransferlib[detectron2]
+pip install git+https://github.com/facebookresearch/detectron2.git@main
 ```
 
 ### Install from source
 ```
 pip install -r requirements/requirements.txt
 python setup.py bdist_wheel
 pip install ../ColorTransferLib/dist/ColorTransferLib-2.0.3-py3-none-any.whl 
-pip install ../ColorTransferLib/dist/ColorTransferLib-2.0.3-py3-none-any.whl[detectron2]
+pip install git+https://github.com/facebookresearch/detectron2.git@main
 ```
 
 ## Usage

setup.py

@@ -31,10 +31,7 @@
     python_requires='>=3.10,<3.11',
     long_description=long_description,
     long_description_content_type='text/markdown',
-    install_requires= requirements,
-    extras_require={
-        'detectron2': ['detectron2 @ git+https://github.com/facebookresearch/detectron2.git@main']
-    }
+    install_requires= requirements
 )
 
 # run seperately: "pip install opencv-python==4.9.0.80 --no-binary opencv-python"