Org-mode syntax as an alternative to Markdown

### Describe the feature or problem you'd like to solve

I would love support for org-mode syntax in Copilot CLI

### Proposed solution

The CLI currently renders assistant responses assuming Markdown. Users who prefer Org-mode syntax (e.g.
Emacs users) can instruct Copilot to respond in Org-mode via a =copilot-instructions.md= file, but the terminal
UI does not render it — code blocks in particular collapse onto a single line, making them unreadable.

Also note that Org-mode syntax has more features than Markdown, allowing for richer output and more use cases,
like notebook-style literate programming.

### Example prompts or workflows

Example: When Copilot outputs this Org-mode code block:

: #+begin_src bash : build testpp_sr : #+end_src

...it renders in the terminal as a single line: =#+begin_src bash build testpp_sr #+end_src=

Requested behaviour: Either (a) render Org-mode syntax natively when detected or configured, respecting block
structure and indentation; or (b) at minimum, preserve newlines faithfully in raw output mode so that
non-Markdown formats remain legible.

### Additional context

Why it matters: Org-mode is widely used in the Emacs ecosystem and is a fully-featured alternative to Markdown
for literate documentation and structured text. Users working in Org-mode-centric workflows would benefit from
first-class support or at least non-destructive rendering.