Move download of weights inside build folder

Signed-off-by: Micaela Verucchi <micaelaverucchi@gmail.com>

README.md

@@ -29,7 +29,7 @@ This branch works on every NVIDIA GPU that supports the dependencies:
 * CUDA 10.0
 * CUDNN 7.603
 * TENSORRT 6.01
-* OPENCV 4.1
+* OPENCV 3.4
 * yaml-cpp 0.5.2 (sudo apt install libyaml-cpp-dev)
 
 ## About OpenCV
@@ -60,10 +60,9 @@ Steps needed to do inference on tkDNN with a custom neural network.
 
 ## How to export weights
 
-Weights are essential for any network to run inference. For each test a folder organized as follow is needed:
+Weights are essential for any network to run inference. For each test a folder organized as follow is needed (in the build folder):
 ```
     test_nn
-        |---- test_nn.cpp (nn definition in tkDNN)
         |---- layers/ (folder containing a binary file for each layer with the corresponding wieghts and bias)
         |---- debug/  (folder containing a binary file for each layer with the corresponding outputs)
 ```
@@ -119,14 +118,15 @@ rm yolo3_FP32.rt        # be sure to delete(or move) old tensorRT files
 ./test_yolo3            # run the yolo test (is slow)
 ./demo yolo3_FP32.rt ../demo/yolo_test.mp4 y
 ```
-In general the demo program takes 3 parameters:
+In general the demo program takes 4 parameters:
 ```
-./demo <network-rt-file> <path-to-video> <kind-of-network>
+./demo <network-rt-file> <path-to-video> <kind-of-network> <number-of-classes>
 ```
 where
 *  ```<network-rt-file>``` is the rt file generated by a test
 *  ```<<path-to-video>``` is the path to a video file or a camera input  
 *  ```<kind-of-network>``` is the type of network. Thee types are currently supported: ```y``` (YOLO family), ```c``` (CenterNet family) and ```m``` (MobileNet-SSD family)
+*  ```<number-of-classes>```is the number of classes the network is trained on
 N.b. By default it is used FP32 inference
 
 ![demo](https://user-images.githubusercontent.com/11562617/72547657-540e7800-388d-11ea-83c6-49dfea2a0607.gif)