Moved Benefits pages into their own folder
Removed manual tags/layout metadata from /docs/extend*
Removed unused e-junkue lib reference
Added /docs/benefits index page
Added Categories system (required a change to Hardwired)
Removing referenced to plugin_page layout
Removed tag/layout/etc metadata from releases; we'll re-apply it with categories. Set layout on index page to 'page', as exception instead of rule.
Removed custom layouts for various categories
Made category medata support generic
Site.rb: Removed plugin_page layout default. Also added missing link checker helper
Modified default layout to support sidebar via metadata and be category-aware
Rewrote /docs homepage
Made sidebars for /docs (use), /plugins and /docs/releases
Added wording to hint OS projects get special help, disabled sidebar
Hide /docs/old-examples
Removed custom layout definitions, switched to tags instead for categories
Install sidebar now lists migration pages, system requiremenst, and hosting pages
Merge remote-tracking branch 'refs/remotes/github/smart-theme-migration' into smart-theme-migration