Rework index.html to remove mistitled links
Rework index.html to remove mistitled links

- Also, clean up prose a bit
- Remove list of APIs and CLIs and replace with links to current
  information instead

Change-Id: Ied2353b1aa3b150772bee4e908fac72d805aef7c
Closes-Bug: #1530550

Tesora/tesora-api-site,Tesora/tesora-api-site,Tesora/tesora-api-site,Tesora/tesora-api-site,openstack/api-site,Tesora/tesora-api-site,Tesora/tesora-api-site,Tesora/tesora-api-site,openstack/api-site,openstack/api-site,openstack/api-site