update and modify documentation (#161)

README.md

@@ -28,7 +28,7 @@ Run the following command to try the demo:
 # detect on camera input
 python demo.py
 # detect on an image
-python demo.py --input /path/to/image
+python demo.py --input /path/to/image -v
 
 # get help regarding various parameters
 python demo.py --help
@@ -40,13 +40,13 @@ Install latest OpenCV and CMake >= 3.24.0 to get started with:
 
 ```shell
 # A typical and default installation path of OpenCV is /usr/local
-cmake -B build -D OPENCV_INSTALLATION_PATH /path/to/opencv/installation .
+cmake -B build -D OPENCV_INSTALLATION_PATH=/path/to/opencv/installation .
 cmake --build build
 
 # detect on camera input
 ./build/demo
 # detect on an image
-./build/demo -i=/path/to/image
+./build/demo -i=/path/to/image -v
 # get help messages
 ./build/demo -h
 ```