Design update

[rschwabco]

Problem

Overall look and feel of the app leaves a lot to be desired.

Solution

Major updates to the UX/UI. This includes:

1. Overhauling the look and feel of the app
2. Removing the cards from the sidebar and moving to inline citations
3. Giving clear indication to the user as to when their index is empty
4. Dual chat displays chat with and without Pinecone

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Infrastructure change (CI configs, etc)
• Non-code change (docs, etc)
• None of the above: (explain here)

[zackproser]

Looks like the playwright tests are failing:

• https://github.com/pinecone-io/pinecone-vercel-starter/actions/runs/7452516898/job/20275971902?pr=30
• https://github.com/pinecone-io/pinecone-vercel-starter/actions/runs/7452615945/job/20276273821?pr=30

We should either fix these up or remove them, if they're no longer desired / there's a better way.