Baseline MAINTAINERS, CODEOWNERS, and external collaborator permissions

[dblock]

Follow opensearch-project/.github#125 to baseline MAINTAINERS, CODEOWNERS, and external collaborator permissions.

Close this issue when:

1. MAINTAINERS.md has the correct list of project maintainers.
2. CODEOWNERS exists and has the correct list of aliases.
3. Repo permissions only contain individual aliases as collaborators with maintain rights, admin, and triage teams.
4. All other teams are removed from repo permissions.

If this repo's permissions was already baselined, please confirm the above when closing this issue.

[dblock]

You have the sql group with 18 members that has maintain access to this repo. Only folks listed in MAINTAINERS/CODEOWNERS need to have maintain access, and groups don't support external collaborators. Please work with an admin to remove the group and add individuals.

[dblock]

[bbarani]

Added the users listed in MAINTAINERS.md file as maintainers of this repo. @anirudha @joshuali925 Please add CODEOWNERS file under .github directory with the maintainers list. CC: @dblock @CEHENKLE

Also, I am not able to add MaxKsyunz and Yury-Fridlyand as they are not part of the organization yet. Please update the maintainers list as needed.

[derek-ho]

This is done, pending adding yury and max to github, which I have opened a ticket for

[dblock]

Verified, thx.