Release `createReducer/createSlice` object argument codemods

[markerikson]

They're currently in #2303 , which needs to be updated. We should release them alongside 1.9 to give folks a chance to more easily update and avoid the warnings.

[markerikson]

We should use https://github.com/reactjs/react-codemod as an example of publishing these, I think.

Other resources:

• https://www.codeshiftcommunity.com/docs/
  • https://www.codeshiftcommunity.com/docs/ecosystem
• https://gist.github.com/caseywatts/b8fffb51180fe44cd3706407d61150a3

[markerikson]

The codemods got merged into their own folder in #2602 , but we need to figure out how to package and publish these, and have instructions for people to use them.

Would love help with this!

[markerikson]

Done! Published as @reduxjs/rtk-codemods . Can tweak and update as needed.