[docker] Adding draft notice.

Author: Murilo M. Marinho

docs/source/docker/index.rst

@@ -1,6 +1,10 @@
 How is Murilo using :program:`docker`
 =====================================
 
+.. important::
+
+    This section is a working draft.
+
 Installation
 ------------
 .. note::
@@ -101,12 +105,13 @@ Docker compose
 ++++++++++++++
 
 If your host does not have :program:`ROS2` you can also have multiple containers communicating with each
-other without any direct involvement of the host. For instance with the following compose file.
+other without any direct involvement of the host. For instance with the following compose file named
+:file:`compose.yml` below.
 
 .. literalinclude:: scripts/composer/simple_example/compose.yml
    :language: yaml
 
-That we can execute with the following command
+In the folder where :file:`compose.yml` exists, we do
 
 .. code-block::
 
@@ -118,6 +123,9 @@ That we can execute with the following command
     around for docker compose to do something similar to ``--rm`` as in :program:`docker`. In tutorials it
     is convenient to always start frash but this will cause data to be lost in the container when it's closed.
 
+This will show the output of the two images communicating over :program:`ROS2`. Notice that there is no input
+from the host and no complicated network setup involved.
+
 You can stop the process with ``CTRL+C``. Note that we are using ``stop_signal: SIGINT`` in the docker compose
 file because otherwise it will send ``SIGTERM``. In this toy example this is not an issue, but this is a major
 issue for nodes that control real resources. This can mean that a robot will not be safely disconnected before
@@ -126,6 +134,11 @@ to give the container enough time to close safely. Depending on your resource yo
 value so that it is not escalated into a ``SIGTERM`` or ``SIGKILL`` before your container had enough time to
 sort out its shutdown procedure.
 
+Docker container in a realtime kernel
+-------------------------------------
+
+TODO
+
 Common mistakes
 ---------------