Update the registry stack PR review process

[thepetk]

What does this PR do?:

This PR updates the contributing guide, adding a section to describe the process followed by the devfiles team regarding the review of PRs updating stacks content.

Other than the contributing guide, it removes all OWNERS files and moves all related information inside the .github/CODEOWNERS file.

Which issue(s) this PR fixes:

fixes devfile/api#1498
fixes devfile/api#1525

PR acceptance criteria:

• Contributing guide
  Have you read the devfile registry contributing guide and followed its instructions?
• Test automation
  Does this repository's tests pass with your changes?
• Documentation
  Does any documentation need to be updated with your changes?
• Check Tools Provider
  Have you tested the changes with existing tools, i.e. Odo, Che, Console? (See devfile registry contributing guide on how to test changes)

How to test changes / Special notes to the reviewer:

[thepetk]

WIP Because:

1. all codeowners need to have write access to the devfile registry repo
2. the devfile-services-team needs to be the only one with permissions to merge a PR

[thepetk]

WIP Because:

1. all codeowners need to have write access to the devfile registry repo
2. the devfile-services-team needs to be the only one with permissions to merge a PR

The above blockers were resolved, removed the WIP label

[Jdubrick]

You might need to force push the sign off for the commits to clear DCO @thepetk

[thepetk]

You might need to force push the sign off for the commits to clear DCO @thepetk

Yeap :) I want to make small update to the CODEOWNERS file so I'll fix it once I push my new commits

[michael-valdron]

@ibuziuk is adding a new ollama stack that will need the OWNERS file refactored as well: #387

Since that PR needs merging by the weeks end, I'd suggest we wait for that change then refactor that OWNERS file into CODEOWNERS here, that way we don't need an extra PR and it still should be completed by sprints end. @thepetk wdyt?

[michael-valdron]

Looks good to me, should include someone from team che to approve as well.

[thepetk]

Looks good to me, should include someone from team che to approve as well.

I've already requested review from @ibuziuk :)

[Jdubrick]

/lgtm

[thepetk]

@michael-valdron as you have requested changes in the past, could you review the updated version of the PR?

[michael-valdron]

/lgtm

[dmytro-ndp]

looks good to merge

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dmytro-ndp, ibuziuk, Jdubrick, michael-valdron, thepetk

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