docs: stop installing kolla in quickstart

We don't need kolla to use kolla-ansible, and installing it makes the
start less quick.

Change-Id: I81d2dae0f8f4d0d4c6e359e1d7d954d6e190b742

doc/source/user/quickstart.rst

@@ -206,11 +206,10 @@ see `Kolla Ansible release notes
 Install Kolla for development
 -----------------------------
 
-#. Clone ``kolla`` and ``kolla-ansible`` repositories from git.
+#. Clone ``kolla-ansible`` repository from git.
 
    .. code-block:: console
 
-      git clone --branch |KOLLA_BRANCH_NAME| https://opendev.org/openstack/kolla
       git clone --branch |KOLLA_BRANCH_NAME| https://opendev.org/openstack/kolla-ansible
 
 #. Install requirements of ``kolla`` and ``kolla-ansible``:
@@ -219,14 +218,12 @@ Install Kolla for development
 
    .. code-block:: console
 
-      pip install ./kolla
       pip install ./kolla-ansible
 
    If not using a virtual environment:
 
    .. code-block:: console
 
-      sudo pip3 install ./kolla
       sudo pip3 install ./kolla-ansible
 
 #. Create the ``/etc/kolla`` directory.