This setting allows us to reference jinja2 and python stdlib docs
via docutils refs instead of hardcoding urls.
Fixes#18039
Remove extraneous sphinx config
* cleanup to reflect current builds
* consolidate templating docs and minor rewording
* new templating intro page
* fixed warnings as per feedback
* Update playbooks_filters.rst
Edited for clarity.
* Update playbooks_templating.rst
Light edits
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'
