docs(cohere): add absolute recipe links and remove dead blog reference (#3526)

Add GitHub absolute URLs to the four North Micro Vision recipe YAMLs in
the Example Recipe table, and remove the non-existent HuggingFace blog
post from the References section.

Signed-off-by: Huiying Li <willwin.lee@gmail.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>