updated plugin docs (#30490)

* updated  docs

- for devs:
  - added inventory/vars section
  - made some updates to general section and other plugin types
- for users:
 - added 'user' plugin section to start describing the plugins
 - docs on types, what they are and how to use

- removed ref to deleted AUTHORS file
- corrected several typos/headers
- added descriptions to config.rst template
- ignore generated files for cli/plugins and config
- remove new generated files on `make clean`
- moved details from devguid and intro doc to plugin specific pages
- pretied up lookup notes
- changed precedence ref to not conflict config
- removed duplicate config data, as config is autogenerated and up to date
- put new plugins under playbooks
- added `pass` cause rst/python dislikes fractions
- removed dupe in .gitignore, alpha sorted to avoid moar dupes
- added try cause rst/python freaks out

* generate plugins into their own dir

only do plugins that support docs
use toctree from main plugins page

docs/docsite/rst/plugins/shell.rst

@@ -0,0 +1,36 @@
+Shell Plugins
+-------------
+
+These plugins work behind the scenes making sure the basic commands Ansible runs,
+in order to be able to execute a task's action,
+are properly formated to work with the target machine.
+
+You normally don't have to wory about these plugins at all,
+unless you have a restricted or exotic setup,
+in which the default ``/bin/sh`` is not a POSIX compatible shell or not availble for execution.
+
+Enabling Shell Plugins
+++++++++++++++++++++++
+
+You probably never need to do this, but aside from the defaul configuration settings in :doc:`../config`,
+you can use a 'connection variable' :ref:`ansible_shell_type` to select the plugin to use,
+you will also want to update the :ref:`ansible_executable` to match.
+
+.. seealso::
+
+   :doc:`../playbooks`
+       An introduction to playbooks
+   :doc:`inventory`
+       Ansible inventory plugins
+   :doc:`callback`
+       Ansible callback plugins
+   :doc:`../playbooks_filters`
+       Jinja2 filter plugins
+   :doc:`../playbooks_tests`
+       Jinja2 test plugins
+   :doc:`../playbooks_lookups`
+       Jinja2 lookup plugins
+   `User Mailing List <http://groups.google.com/group/ansible-devel>`_
+       Have a question?  Stop by the google group!
+   `irc.freenode.net <http://irc.freenode.net>`_
+       #ansible IRC chat channel