Revamp highlights on website homepage

[deepthi]

It will be nice to revamp the main homepage to highlight features that may be more relevant today compared to 5 years ago.

Current state:

To start with I'm going to document some of the suggestions that have come up. We can have some discussion on this issue and then finalize the 6 highlights we want to have with associated text.

• Online schema changes
• While Shard management sort of gets at this, we want to highlight how easy it is to migrate into Vitess, and to "MoveTables", with close to zero downtime.
• High availability is missing (sort of covered under Manageability by saying "Failovers")
• Backups and restores should be their own highlight
• Connection Pooling can become a feature under performance instead of its own section.
• Workflow can probably be removed
• Materialized Views
• Messaging
• Vindexes aka flexible sharding keys. We say "without adding sharding logic to application", but don't highlight how flexible vitess sharding is

Thanks to @timvaillancourt for raising this and providing many of these suggestions. And to @derekperkins and @shlomi-noach for their follow up suggestions and commentary.