Generate rst docs for plugins
Based on rst generated for modules. But generated plugin
docs go into docs/docsite/rst/plugins/$PLUGIN_TYPE/plugin_name.rst
( docs/docsite/rst/plugins/connection/ssh.py for ex)
* move plugins docs to rst/*_plugins/ subdirs for namespace
* Only gen support pages for modules for now.
* Add generated plugin docs to gitignore* add list_*_plugins templates
* support MODULES/PLUGINS filters for make htmldocs
Add a 'PLUGINS=ssh' filter env var like MODULES to filter plugins to build docs for.
* fixup 'historical' version_added, skip plugins/loader.py
* Fix plugins_by_support ref link to new plugins/*/ location
* use :ref: for common_return_values, allow empty version_added
* warnings on missing doc info
* add a prefix to _random_choice
It was colliding with the target for random_choice plugin
Replace docs build-site.py with default-ish sphinx build
This seems to speed up docsite build _alot_.
The Makefile.sphinx is the sphinx-quickstart generated makefile with a few changes.
The CPUS env var or 'nproc' output is used for the number of cpus passed to 'sphinx-build -j'
