Update intro_dynamic_inventory.rst (#15750)

When using Cobbler with Ansible a cobbler.ini file is needed by the /etc/ansible/cobbler.py script, otherwise Python errors like ConfigParser.NoSectionError: No section: 'cobbler' are shown. Maybe this could be added to the documentation. Thanks and cheers!

docsite/rst/intro_dynamic_inventory.rst

@@ -34,6 +34,28 @@ To tie Ansible's inventory to Cobbler (optional), copy `this script <https://raw
 to be running when you are using Ansible and you'll need to use Ansible's  ``-i`` command line option (e.g. ``-i /etc/ansible/cobbler.py``).
 This particular script will communicate with Cobbler using Cobbler's XMLRPC API.
 
+Also a cobbler.ini file should be added to /etc/ansible so Ansible knows where the Cobbler server is and some cache improvements can be used. For example::
+
+
+    [cobbler]
+
+    # Set Cobbler's hostname or IP address
+    host = http://127.0.0.1/cobbler_api
+
+    # API calls to Cobbler can be slow. For this reason, we cache the results of an API
+    # call. Set this to the path you want cache files to be written to. Two files
+    # will be written to this directory:
+    #   - ansible-cobbler.cache
+    #   - ansible-cobbler.index
+
+    cache_path = /tmp
+
+    # The number of seconds a cache file is considered valid. After this many
+    # seconds, a new API call will be made, and the cache file will be updated.
+
+    cache_max_age = 900
+
+
 First test the script by running ``/etc/ansible/cobbler.py`` directly.   You should see some JSON data output, but it may not have anything in it just yet.
 
 Let's explore what this does.  In cobbler, assume a scenario somewhat like the following::