If you like the man page aesthetic, using pandoc with groff is the most readable way to read markdown on the terminal I've found:

    mdless() {
        if command -v pandoc >/dev/null; then
            if [[ -z "$1" ]]; then
                cat | pandoc -s -f markdown -t man | groff -T utf8 -man | less
            else
                pandoc -s -f markdown -t man "$*" | groff -T utf8 -man | less
            fi
        else
            less "$@"
        fi
    }