message: docs: added some more examples
diff: @@ -26,9 +26,31 @@ You can create your own Field Extension by using the
  ```tsx
  //packages/app/scaffolder/MyCustomExtension/MyCustomExtension.tsx
  -export const MyCustomExtension = () => {};
  +import { FieldProps } from '@rjsf/core';
  +export const MyCustomExtension = ({ onChange, required }: FieldProps<string>) => {
  + return (
  + <FormControl
  + margin="normal"
  + required={required}
  + error={rawErrors?.length > 0 && !formData}
  + >
  + )
  +};
  ```
  ```tsx
  // packages/app/scaffolder/MyCustomExtension/validation.ts
  +import { FieldValidation } from '@rjsf/core';
  +import { KubernetesValidatorFunctions } from '@backstage/catalog-model';
  +
  +export const myCustomValidation = (
  + value: string,
  + validation: FieldValidation,
  +) => {
  + if (!KubernetesValidatorFunctions.isValidObjectName(value)) {
  + validation.addError(
  + 'must start and end with an alphanumeric character, and contain only alphanumeric characters, hyphens, underscores, and periods. Maximum length is 63 characters.',
  + );
  + }
  +};
  ```
  