Doug Kearns is joining the project as maintainer

[Christian Brabandt]

Dear Vim friends,

I am pleased to announce that Doug Kearns will be joining our project.
Doug brings experience and expertise to our team especially when working
on the included runtime files.

Doug has a proven track record in helping the project especially with
the bundled syntax and filetype plugins, as well has actively
contributed in the Vim9 language discussion and I am confident that his
insights and contributions will greatly benefit our project.

Thanks,
Christian