David Muir has been one of the many public figures to pay tribute to General Colin Powell following his death aged 84.MORE: Inside David Muir's $7million home - complete with his own lake The former US Secretary of State tragically passed away from Covid-19 complications on 18 October, and David wrote a powerful message where he listed 13 rules that Colin lived by, which was posted alongside a selfie of him as a young man.The Good Morning America star penned: "General Colin Powell posted this a