added contributor guide and updated owner

[anithapriyanatarajan]

Changes

This pull request introduces new contribution guidelines for the project and updates the list of code owners and reviewers.

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• Has Docs if any changes are user facing, including updates to minimum requirements e.g. Kubernetes version bumps
• Has Tests included if any functionality added or changed
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/kind documentation

Release Notes

NONE

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[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: savitaashture

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[savitaashture]

/lgtm