configure document root directory for gitlab mattermost

Hi,

I'm trying to set up Let's Encrypt for Gitlab Mattermost. The configuration script for Let's Encrypt needs to put a temporary file in mattermost.example.com/.well-known/some_random_string. The configuration currently allows me to access

/opt/gitlab/embedded/service/mattermost/web/static/

but not things inside the actual document root directory, which is just

/opt/gitlab/embedded/service/mattermost/web/

Any ideas as to how I can enable read access for files in the root directory?

Here is some information about Gitlab Mattermost and how it configures nginx

https://github.com/gitlabhq/omnibus-gitlab/blob/master/doc/settings/nginx.md


Thanks