Docsite/dev_guide: add note about ansible-test utility installation ways (#76128)

* Docsite/dev_guide: add note about ansible-test utility installation
* Add link to Testing Ansible page

docs/docsite/rst/dev_guide/developing_collections_testing.rst

@@ -13,7 +13,9 @@ Testing your collection ensures that your code works well and integrates well wi
 Testing tools
 =============
 
-The main tool for testing collections is ``ansible-test``, Ansible's testing tool described in :ref:`developing_testing`. You can run several compile and sanity checks, as well as run unit and integration tests for plugins using ``ansible-test``. When you test collections, test against the ansible-core version(s) you are targeting.
+The main tool for testing collections is ``ansible-test``, Ansible's testing tool described in :ref:`developing_testing` and provided by both the ``ansible`` and ``ansible-core`` packages.
+
+You can run several compile and sanity checks, as well as run unit and integration tests for plugins using ``ansible-test``. When you test collections, test against the ansible-core version(s) you are targeting.
 
 You must always execute ``ansible-test`` from the root directory of a collection. You can run ``ansible-test`` in Docker containers without installing any special requirements. The Ansible team uses this approach in Azure Pipelines both in the ansible/ansible GitHub repository and in the large community collections such as `community.general <https://github.com/ansible-collections/community.general/>`_ and `community.network <https://github.com/ansible-collections/community.network/>`_. The examples below demonstrate running tests in Docker containers.