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]

The permissions are incorrect.

• You have a group with 12 members as maintainers, add them individually with maintainer level access similar to how you'd do external contributors.
• Add triage group with triage access.

@bbarani's team can help

[bbarani]

Fixed the permissions now to reflect the users in MAINTAINERS file. Closing this issue.

[dblock]

Verified, thanks.