Allowing mkdocs-monorepo.yml to integrate existing mkdocs site without breaking configuration

[rkttu]

Thank you for making this useful tool. I have one suggestion.

I can't seem to be able to use any file name other than mkdocs.yml. Can you allow the existing site to use the mkdocs.yml file, and use a different configuration file when connecting to monorepo?

This will allow for a more various configuration and will be useful.