* inventory plugin docs
* added set options
* minor wording and formatting fixes
* changed headers to std as per #35520, also added to main readme
* unified inventory plugin devel, referenced from generic plugin dev
* fixed typos and update as per feedback
* 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
* developing_modules.rst is now in dev_guide, sync changes and delete the old version
* Cleaner RST & formatted code
* Tidyup roadmaps
* Link to repomerge
* Pull in abadger's fixes From https://github.com/ansible/ansible/compare/docs-code-block-fixes?expand=1
* Clean docsite/rst (apart from ROADMAP
