Tweaks to layouts and styles

• On docs homepage add runner block alongside other three blocks.
• Move the ToC sidebar to the right.
• If there is only one h1 element in the doc remove it from the sidebar nav and add it as a sidebar title. This will free up horizontal space for nesting.
• If there is only one breadcrumb item, e.g on top level index pages such as CE, EE etc don't show the breadcrumbs.
• Add a "quick links" sidebar for top level topics and frequently accessed docs (coding).
• Add a middle break point to hide the quick links sidebar
• Create a quick links list (content) for CE, EE, Runner, Omnibus will be done in a future issue.