fix: added rbac guide for keto

[gen1us2k]

Related Issue or Design Document

Checklist

• I have read the contributing guidelines
  and signed the CLA.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I have read the security policy.
• I confirm that this pull request does not address a security
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• I have added tests that prove my fix is effective or that my feature
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• I have added necessary documentation within the code base (if
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Further comments

[gen1us2k]

@hperl @zepatrik Hello. I fixed everything and it looks fine now. The guide uses keto cli instead of curl examples. WDYT?

[hperl]

@hperl @zepatrik Hello. I fixed everything and it looks fine now. The guide uses keto cli instead of curl examples. WDYT?

Thanks, LGTM!

[hperl]

@zepatrik LGTM, but I can't approve. Can you?