* orphans testing pages to avoid not-in-toctree errors
* orphans various pages pending reorg
* adds module_utils and special_vars to main TOC
* uses a glob for scenario_guide TOC
* normalize and Sentence-case headings on community pages, typos
* re-orgs community TOC, adds all pages to toctree
* removes scenario guides index page
* adds style guide to community index
* basic update to style guide
* fix typo that created a new error
* removes not-in-toctree from ignore errors list
* leave removing files for future cleanup task
Extends `module_defaults` by adding a prefix to defaults `group/` which denotes a builtin list of modules. Initial groups are: `group/aws`, `group/azure`, and `group/gcp`
