Add descriptions of git_sparse_download.sh/bat in README.md

Author: dmitrygolovkin

README.md

@@ -26,7 +26,27 @@ git version 2.9.3 # or newer
 ```
 3.  Add [SSH key](https://help.github.com/articles/adding-a-new-ssh-key-to-your-github-account/) to your GitHub account (if you haven't already)
 
-4. clone the repo:
+4. clone the full repo:
 ```
 $ git clone https://github.com/foss-for-synopsys-dwc-arc-processors/synopsys-caffe-models.git
 ```
+
+5. clone a part of the repo:
+```
+If you don't need all models and want to save disc space you can use special scripts:
+
+git_sparse_download.sh  - for Linux
+git_sparse_download.bat - for Windows
+
+They set-up git repo for working in space-checkout mode, with minimum git history
+
+1. Choose a folder where "cnn_models" folder will be created. 
+2. Select on "Save link as .." to save the script in that folder
+2. Choose a list of models which you want to work with ( in caffe_models folder), for instance: googlenet mobilenet
+3. Run the script with params - names of selected models:
+Example:
+git_sparse_download.sh googlenet mobilenet
+
+It creates "cnn_models" folder, init git repo in there, dowload common files and models you select.
+
+```