Add support for markdown code blocks/syntax highlighting

[Azzeo]

There is currently no style applied to fenced code blocks. When the user submits a code block, there is no style applied and instead just shows the plain text. Furthermore, when the user asks for a piece of code (or a quote) in a fenced code, it is not rendered in the prompt response block. We all know this feature in the ChatGPT UI, where code/quotes are highlighted, with the addition of a copy button to easily copy the piece of code/quote

Example for Ruby:

def index
  puts "hello world"
end

(Github doesn't show the name of the programming language, but this is additionally shown by i.e., ChatGPT and Bard)

How it's currently rendered:

def index
puts "hello world"
end

[crickman]

Thanks for reporting this. While chat-copilot does perform some formatting (markdown), this is a great scenario to identify.