Tweaks to the look of EmilyAI V2

[lukeocodes]

Branching off of release/agent-api please see to the following frontend tweaks

1. Update the banner to read "EmilyAI v2 powered by Deepgram" reusing the existing banner for "powered by Deepgram" and adding the extra parts. See the mock ups for example:
   
   

https://community.deepgram.com has an example of this styling with tailwind classes

2. Introduce a new line in the banner that in light-grey text, below the heading mentioned above, includes "Uses Deepgram's unified voice to voice API"

3. On this secondary heading line, include a link to "Switch to EmilyAI v1 - using STT / LLM / TTS". The link URL will be https://emilyai-v1.deepgram.com (which doesn't exist yet, but it will).

4. Update the landing page to read "Welcome to Deepgram's Voice Agent API Demo".

5. Update the landing page list (shown in the screenshot) to read

• Deepgram's Voice Agent API
• Claude 2 Haiku
  

6. General CSS tidy up of chat interface (i.e. inconsistent font sizes, borders)