Update documents in the Aries OCA Bundle repo to make sense on the published site

[swcurran]

• Update the repo README to reference the docs site
• Update the docs site README to talk about the structure of the data
• Add the OCA Bundles to the docs site to make the paths work
• Verify the links work on the published site
• Add text to the placeholder readme files

[swcurran]

Completed via #123