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/dev_guide/testing/sanity/ansible-var-precedence-check.rst

@@ -1,4 +1,4 @@
 Sanity Tests » ansible-var-precedence-check
 ===========================================
 
-Check the order of precedence for Ansible variables against :ref:`variable_precedence`.
+Check the order of precedence for Ansible variables against :ref:`ansible_variable_precedence`.