mdl: Don't enforce one space after list markers
Common markdown styles usually show 4-column indents to separate the
list marker and the list item text. That's a common template for
writing new markdown files.
On the other hand, we do have some files (such as CHANGES.md) where we
use a different style.
From a markdown perspective, both are perfectly OK, and there's no
reason to enforce either.
Therefore, the best thing is to exclude this particular rule.
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18297)