Added layouts for tab containers so you don't need to do html
Merge remote-tracking branch 'origin/master' into add-liquid-templates
Added templates for alert boxes, made the tab ones work

Note: things are still not great, it is finicky
merged more tab panes over to use includes
switched existing alerts over to use includes
Added expander capability, implemented it in suggested practices patterns vs. instances
Moved the observable practices into the observable section
Suggested practice for title/desc/short desc
Merge pull request #126 from STIXProject/add-liquid-templates

Add liquid templates for alerts, tabs, and expanders