Add filenames to code snippets under Setup docs page (#540)

website/docs/getting-started/setup.md

@@ -10,8 +10,7 @@ sidebar_position: 2
 
 Create a setup script with the following:
 
-```javascript
-// ./testSetup.js
+```javascript title="testSetup.js"
 
 // add all jest-extended matchers
 import * as matchers from 'jest-extended';
@@ -24,15 +23,15 @@ expect.extend({ toBeArray, toBeSealed });
 
 Add your setup script to your Jest `setupFilesAfterEnv` configuration. [See for help](https://jestjs.io/docs/en/configuration.html#setupfilesafterenv-array)
 
-```json
+```json title="package.json"
 "jest": {
   "setupFilesAfterEnv": ["./testSetup.js"]
 }
 ```
 
 To automatically extend `expect` with all matchers, you can use
 
-```json
+```json title="package.json"
 "jest": {
   "setupFilesAfterEnv": ["jest-extended/all"]
 }
@@ -42,15 +41,15 @@ To automatically extend `expect` with all matchers, you can use
 
 `jest-extended` works with `vitest` because their `expect.extend` API is compatible. In your setup script:
 
-```javascript
+```javascript title="testSetup.js"
 import {expect} from "vitest";
 import * as matchers from "jest-extended";
 expect.extend(matchers);
 ```
 
 Add this setup script to your `vitest.config.js`:
 
-```javascript
+```javascript title="vitest.config.js"
 export default defineConfig({
   test: {
     setupFiles: ["./testSetup.js"],