feat(kratos): add statefulset.extraArgs option

[Davincible]

Also fix capitalization in readme.md

Fix: #486

Related Issue or Design Document

Checklist

• [x] I have read the contributing guidelines and signed the CLA.
• [x] I have referenced an issue containing the design document if my change introduces a new feature.
• [x] I have read the security policy.
• [x] I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security vulnerability, I confirm that I got green light (please contact [email protected]) from the maintainers to push the changes.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [x] I have added necessary documentation within the code base (if appropriate).

Further comments

[CLAassistant]

All committers have signed the CLA.

[Davincible]

I was confused as in the same helm template, both statefulSet and statefulset were used. I changed all to the former since it aligns more with the rest of the conventions used throughout the template. This is a breaking change, however.

[Demonsthere]

I see, good catch with the statefulset, looks like a leftover that was missed when we were refactoring the chart. It is a breaking change, but for the sake of consistency I am in favour of merging it