[docker] Publish installed packages in docker containers (#35390)

This PR adds information about the installed packages in our Docker images to the Ray docs.

Signed-off-by: Kai Fricke <kai@anyscale.com>

doc/source/ray-overview/installation.rst

@@ -495,3 +495,27 @@ that you've cloned the git repository.
 .. code-block:: bash
 
   python -m pytest -v python/ray/tests/test_mini.py
+
+
+Installed Python dependencies
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Our docker images are shipped with pre-installed Python dependencies
+required for Ray and its libraries.
+
+We publish the dependencies that are installed in our ``ray`` and ``ray-ml``
+Docker images for Python 3.9.
+
+.. tabs::
+
+    .. group-tab:: ray (Python 3.9)
+
+        Ray version: nightly (`0d880e3 <https://github.com/ray-project/ray/commit/0d880e351d3c52bcb84207e397c531088c11ffda>`_)
+
+        .. literalinclude:: ./pip_freeze_ray-py39-cpu.txt
+
+    .. group-tab:: ray-ml (Python 3.9)
+
+        Ray version: nightly (`0d880e3 <https://github.com/ray-project/ray/commit/0d880e351d3c52bcb84207e397c531088c11ffda>`_)
+
+        .. literalinclude:: ./pip_freeze_ray-ml-py39-cpu.txt