[docs] remove not working dev setup

also add the command to clone the repository
and use the pip-install `--editable` option in
it's long form so it's immediately clear what it does.

Change-Id: I00403f967c06af6d8c718ed1245aaa01f1218add
Signed-off-by: Sven Kieske <[email protected]>

Author: artificial-intelligence

doc/source/contributor/running-in-development.rst

@@ -7,23 +7,15 @@ Running Kolla Build in development
 The recommended way to run in development
 -----------------------------------------
 
-The preferred way to run kolla-build for development is using ``tox``.
-Run the following from inside the repository:
+To clone the repository and install the package
+in development mode, run the following commands:
 
-.. code-block:: console
-
-    tox -e venv -- kolla-build ...
-
-The alternative way to run in development
------------------------------------------
-
-Sometimes, developers prefer to manage their venvs themselves. This is also
-possible. Remember to install in editable mode (``-e``). Run the following from
-inside the repository:
 
 .. code-block:: console
 
+    git clone https://opendev.org/openstack/kolla.git
+    cd kolla
     python3 -m venv ~/path/to/venv
     source ~/path/to/venv/bin/activate
-    python3 -m pip install -e .
+    python3 -m pip install --editable .
     kolla-build ...