DOCS: Add authentication scripts location (#96)

Change-Id: Ie285d80ea6d9bb8f710998208d0aa7c6db661d02

Signed-off-by: Galantsev, Dmitrii <dmitrii.galantsev@amd.com>

[ROCm/rdc commit: 4da277a64e]

projects/rdc/docs/install/handbook.rst

@@ -124,6 +124,7 @@ To generate the keys and certificates using these scripts, make the following ca
 
 .. code-block:: shell
   
+    $ cd /opt/rocm/libexec/rdc/authentication
     $ 01gen_root_cert.sh
     # provide answers to posed questions
     $ 02gen_ssl_artifacts.sh