Update home page layout and content

[huijing]

Closes #320 (putting this here to link to issue)

The team, while working on the revamp of the specification, has also added some branding and layout changes in the link_rel_docs branch. This PR migrates these changes over to the main branch to alleviate the potential for merge conflicts when that mega-branch needs to be merged.

The new layout and content looks like this:

[sublimator]

wallets are gone, a dearth of swiftness lament