docs: Fix python-openstackclient package name and init-runonce path

Related-Bug: #1949198
Change-Id: I2bd1a3674f8dd254b55634903a4c046293557e18
Signed-off-by: Adrian Andreias <adrian@fleio.com>

doc/source/user/quickstart.rst

@@ -539,7 +539,7 @@ Using OpenStack
 
    .. code-block:: console
 
-      pip install python3-openstackclient
+      pip install python-openstackclient
 
 #. OpenStack requires an openrc file where credentials for admin user
    are set. To generate this file:
@@ -562,8 +562,15 @@ Using OpenStack
 #. Depending on how you installed Kolla Ansible, there is a script that will
    create example networks, images, and so on.
 
-   * For deployment or evaluation,
-     run ``init-runonce`` script:
+   * For deployment or evaluation, run ``init-runonce`` script.
+
+     If using a virtual environment:
+
+     .. code-block:: console
+
+        /path/to/venv/share/share/kolla-ansible/init-runonce
+
+     If not using a virtual environment:
 
      .. code-block:: console