add syntax highlighting via themeing

[jaycenhorton]

Related to #333, this approach enables syntax highlighting, including for streaming chats

[TheR1D]

Thank you for the PR @jaycenhorton, looks good! The only thing I don't like about rich markdown render is vertical overflow, when the output text is larger then terminal height, it renders elipsis at last line "...", until we will get full response from API. This is especially noticeable when you have small terminal window (not full screen). For regular user it might be confusing, since it looks like sgpt "hangs".

But this might be usefull for many sgpt users. Can we make it as optional feature? Using .sgptrc we could define something like RENDER_MARKDOWN=true (false by default).

[jeanlucthumm]

Regarding the vertical overflow, in the demo it seems like the terminal just scrolls when it hits the bottom. How is that achieved?

[TheR1D]

Regarding the vertical overflow, in the demo it seems like the terminal just scrolls when it hits the bottom. How is that achieved?

As I described in my previous comment, when having a small terminal window (not full screen), and requesting some long text from LLM (which can't fit in current terminal window height), we will have vertical overflow.

Another thing which I was thinking about it that, by default ShellGPT needs plain text in order to exectue shell comamnds or create valid source code files. So this feature probably will require some tweaks in the default role, which will explicitly require markdown as output from LLM.

[TheR1D]

Implemented in #400 with few role changes. Included @jaycenhorton as Co-Author of the commit, thank you for your interest and effort.