Markdown: Use color with higher contrast for lists
Summary:
BUG: 405824
FIXED-IN: 5.59
Test Plan: make && make test
Reviewers: cullmann, gregormi
Reviewed By: cullmann
Subscribers: kwrite-devel, kde-frameworks-devel
Tags: Kate, Frameworks
Differential Revision: https://phabricator.kde.org/D21293