* Replace InventoryFileCacheModule with a better developer-interface
Use new interface for inventory plugins with backwards compatibility
Auto-update the backing cache-plugin if the cache has changed after parsing the inventory plugin
* Update CacheModules to use the config system and add a deprecation warning if they are being imported directly rather than using cache_loader
* Fix foreman inventory caching
* Add tests
* Add integration test to check that fact caching works normally with cache plugins using ansible.constants and inventory caching provides a helpful error for non-compatible cache plugins
* Add some developer documentation for inventory and cache plugins
* Add user documentation for inventory caching
* Add deprecation docs
* Apply suggestions from docs review
* Add changelog
* update the developing_inventory docs to show ungrouped as a dict with a "children" key; avoid
[WARNING]: Found both group and host with same name: ungrouped
* Changed 'Control Machine' to 'Control Node' in the documentation. Changing the term 'Control Machine' to 'Control Node', to be in line with the basic concepts here: https://docs.ansible.com/ansible/latest/network/getting_started/basic_concepts.html
Also for both entities; Control/Managed using the same common denominator 'Node' brings consistency.
* Updated reference links to new term.
* 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
* 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
