Introduced brief explanation about pulp_installer

https://pulp.plan.io/issues/6674
closes #6674

CHANGES/6674.doc

@@ -0,0 +1 @@
+Introduced a brief explanation about `pulp_installer`

docs/installation/instructions.rst

@@ -23,8 +23,45 @@ Fedora, CentOS, and Mac OSX.
 Ansible Installation (Recommended)
 ----------------------------------
 
-To use ansible roles to install Pulp 3 instead of manual setup refer to
-`Pulp 3 Ansible Installer <https://github.com/pulp/pulp_installer/>`_.
+`Pulp 3 Ansible Installer <https://github.com/pulp/pulp_installer>`_ can be used to
+install plugins. For example if your host is in your Ansible inventory as ``myhost`` you
+can install onto it with:
+
+.. code-block:: bash
+
+    git clone https://github.com/pulp/pulp_installer.git
+
+Create your pulp_install.yml playbook to use with the installer:
+
+.. code-block:: yaml
+
+   ---
+   - hosts: all
+     vars:
+       pulp_settings:
+         secret_key: secret
+         content_origin: "http://{{ ansible_fqdn }}"
+       pulp_default_admin_password: password
+       pulp_install_plugins:
+         pulp-file: {}
+     roles:
+       - pulp-database
+       - pulp-workers
+       - pulp-resource-manager
+       - pulp-webserver
+       - pulp-content
+     environment:
+       DJANGO_SETTINGS_MODULE: pulpcore.app.settings
+
+Then install it onto ``myhost`` with:
+
+.. code-block:: bash
+
+    ansible-playbook pulp_install.yaml -l myhost
+
+
+For learning more about the ansible roles to install Pulp 3 please refer to
+`Pulp 3 Ansible Installer <https://github.com/pulp/pulp_installer/#pulp-3-ansible-installer>`__.
 
 PyPI Installation
 -----------------