Tidy up Contributors Docs (#47619)

* Tidy up docs on GitHub, direct people to docs.ansible.com
* De-duplicate documentation and move useful info

docs/docsite/rst/roadmap/index.rst

@@ -3,7 +3,21 @@
 Ansible Roadmap
 ===============
 
-The Ansible team develops a roadmap for each major Ansible release. The latest roadmap shows current work; older roadmaps provide a history of the project. 
+The Ansible team develops a roadmap for each major and minor Ansible release. The latest roadmap shows current work; older roadmaps provide a history of the project. We don't publish roadmaps for subminor versions. So 2.0 and 2.8 have roadmaps, but 2.7.1 does not.
+
+We incorporate team and community feedback in each roadmap, and aim for further transparency and better inclusion of both community desires and submissions.
+
+Each roadmap offers a *best guess*, based on the Ansible team's experience and on requests and feedback from the community, of what will be included in a given release. However, some items on the roadmap may be dropped due to time constraints, lack of community maintainers, etc.
+
+Each roadmap is published both as an idea of what is upcoming in Ansible, and as a medium for seeking further feedback from the community.
+
+You can submit feedback on the current roadmap in multiple ways:
+
+- Edit the agenda of an IRC `Core Team Meeting <https://github.com/ansible/community/blob/master/meetings/README.md>`_ (preferred)
+- Post on the ``#ansible-devel`` Freenode IRC channel
+- Email the ansible-devel list
+
+See :ref:`Ansible communication channels <communication>` for details on how to join and use the email lists and IRC channels.
 
 .. toctree::
    :maxdepth: 1
@@ -11,4 +25,3 @@ The Ansible team develops a roadmap for each major Ansible release. The latest r
    :caption: Ansible Release Roadmaps
 
    ROADMAP*
-