markdownlint-cli2 doesn't show nvim diagnostic either not fill diagnostic list

[hayer969]

After this commit ca6ea12 in my .md files no more diagnostic available.
Command :lua vim.diagnostic.setloclist() does nothing, no error messages

[clonejo]

As of 4b03656, only .markdownlint-cli2.yaml from the working directory is applied, but a config file right next to the file being edited is ignored.