Fix: Multiline input and empty starter prompt bubble

[0xi4o]

• Changes chat input to multiline so scrolling long inputs is easier
• Fixes an issue where removing all starter prompts creates an empty bubble

[HenryHengZJ]

can we have a screenshot?

[HenryHengZJ]

The new textarea is different in term of font style, padding etc as compared to the old one:

Also, I think we can expand the chatbox a little bit more

[0xi4o]

@HenryHengZJ Fixed the height, padding, and font. Field will also show more lines when the input is long. Here's how it looks now: