Implement CODEOWNERS For Stack Owners

[Jdubrick]

Which area/kind this issue is related to?

/area registry

Issue Description

Currently in the Devfile Registry we have an OWNERS file in the directory for each stack to outline the owner of said stack. We have decided to move to a CODEOWNERS file approach where the owners of each stack will be defined here. In addition to consolidating all of the owners to that CODEOWNERS file we will need to remove the OWNERS file from the stack directories as they are no longer required. The OWNERS file in the root of the registry repository should remain.

Acceptance Criteria

• CODEOWNERSfile edited to include all stacks and their respective owners
• OWNERS files that are apart of each stack removed
• Update root documentation to outline the new process of defining owners

[Jdubrick]

Updated issue title and description as we are shifting to a CODEOWNERS approach rather than having individual OWNERS files for each stack.