chore: update react imports

Signed-off-by: Paul Schultz <pschultz@pobox.com>

docs/features/software-templates/writing-custom-field-extensions.md

@@ -29,7 +29,6 @@ As an example, we will create a component that validates whether a string is in
 
 ```tsx
 //packages/app/src/scaffolder/ValidateKebabCase/ValidateKebabCaseExtension.tsx
-import React from 'react';
 import { FieldExtensionComponentProps } from '@backstage/plugin-scaffolder-react';
 import type { FieldValidation } from '@rjsf/utils';
 import FormControl from '@material-ui/core/FormControl';

docs/features/software-templates/writing-custom-step-layouts.md

@@ -18,8 +18,7 @@ This is the same [field](https://rjsf-team.github.io/react-jsonschema-form/docs/
 
 The [createScaffolderLayout](https://backstage.io/docs/reference/plugin-scaffolder-react.createscaffolderlayout) function is used to mark a component as a custom step layout:
 
-```ts
-import React from 'react';
+```tsx
 import { scaffolderPlugin } from '@backstage/plugin-scaffolder';
 import {
   createScaffolderLayout,