Add details to installation from source instructions (#32)

Signed-off-by: apeganov <[email protected]>

Signed-off-by: apeganov <[email protected]>
Co-authored-by: apeganov <[email protected]>

Author: PeganovAnton

README.md

@@ -35,6 +35,8 @@ case and deliver real-time performance. This repo provides performant client exa
     - Run commands
 
 ```bash
+git clone https://github.com/nvidia-riva/python-clients.git
+cd python-clients
 git submodule init
 git submodule update
 pip install -r requirements.txt