Add Codeowners file

[kilasuit]

[luigilink]

@kilasuit don't hesitate to suggest code when you open an issue. I used the code owner file from sqlserverdsc repo, what do you think?

# cSpell: ignore sharepointdsc
# Each line is a file pattern followed by one or more owners.

# These owners will be the default owners for everything in
# the repo. Unless a later match takes precedence,
# @dsccommunity/sharepointdsc will be requested for review when
# someone opens a pull request.
* @dsccommunity/sharepointdsc
/* @ykuijs