Issue #3461102 by bucefal91: Provide config schema.
requested to merge issue/ckeditor5_markdown_editor-3461102:3461102-ckeditor5markdowneditor.settings.yml-lacks-schema into 1.0.x
Closes #3461102
I guess it is also a good proof for the value of schema. The PHP code of this module would refer to plugin version as plugins_version_installed while the initial config installation would mark it as plugins_installed_version.