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.rst

@@ -0,0 +1,31 @@
+Plugins
+=======
+
+Ansible uses a plugin architecture to enable a rich, flexible and expandible feature set.
+They are pieces of code that augment Ansible's core functionality.
+Ansible ships with a number of handy plugins, and you can easily write your own.
+
+There are many types of plugins, these are the most relevant ones:
+
+.. toctree:: :maxdepth: 1
+    :glob:
+
+    plugins/*
+    playbooks_filters
+    playbooks_tests
+
+Most of the time you are using them without having to know about them, but when you want to change certain behaviours you need to know how to enable,
+activate or trigger each type.
+
+.. seealso::
+
+   :doc:`playbooks`
+       An introduction to playbooks
+   :doc:`config`
+       Ansible configuration documentation and settings
+   :doc:`command_line_tools`
+       Ansible tools, description and options
+   `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