Update readme to account for changes in types and add additional example

[iansan5653]

Note: This is a draft PR because it should not be merged until DefinitelyTyped/DefinitelyTyped#44589 is merged.

• Removes the "Why does InferType not default to nonRequired()" since this is incorrect due to [yup] Make all schemas default to being typed as optional (notRequired) DefinitelyTyped/DefinitelyTyped#44589
• Adds defined calls to the firstName and nickName in the example
• Updates example and adds note for using oneOf`` without using the generic type parameter of mixed` ([yup] Make typing for oneOf work to refine the schema type DefinitelyTyped/DefinitelyTyped#44573)
• Adds an example for how you might ensure that a schema conforms to an interface or type

Note: Does not change the version in package.json.

[iansan5653]

@jquense I went ahead and updated the version in package.json as well as adding the entry to the changelog. I expect you may want to modify the changelog entry to your preference but I figured I would get it started. This should be ready to go and then we can merge the PR in DefinitelyTyped.

[jquense]

one nit

[jquense]

Don't bump the version, the release process will handle that

[iansan5653]

Reverted that ✔️