Dev: Update Documentation Linking

[AdamJ]

Update the documentation linking to match the designs from Design: Documentation links from OSIO.

Three parts:

• [x] Update OSIO landing page navigation
• [x] Update User dropdown in OSIO application header
• [x] Update banner information on OSIO home page

[AdamJ]

Banner Update: https://github.com/fabric8-ui/fabric8-ui/pull/2547

[AdamJ]

User dropdown: https://github.com/fabric8-ui/fabric8-ui/pull/2546

[AdamJ]

Landing page navigation: https://github.com/openshiftio/openshift.io/pull/2277