fix(docs): refine config file extension labels to cjs

Author: jashtanna007

src/content/guides/getting-started.mdx

@@ -248,7 +248,7 @@ As of version 4, webpack doesn't require any configuration, but most projects wi
 
 <CodeBlock label="webpack.config.mjs" active>
 
-```javascript
+````javascript
 import path from 'path';
 import { fileURLToPath } from 'url';
 
@@ -263,7 +263,7 @@ export default {
 };
 </CodeBlock>
 
-<CodeBlock label="webpack.config.cjs / .js">
+<CodeBlock label="webpack.config.cjs">
 const path = require('path');
 
 module.exports = {
@@ -289,7 +289,7 @@ cacheable modules 530 KiB
   ./src/index.js 257 bytes [built] [code generated]
   ./node_modules/lodash/lodash.js 530 KiB [built] [code generated]
 webpack 5.4.0 compiled successfully in 1934 ms
-```
+````
 
 T> If a `webpack.config.js` is present, the `webpack` command picks it up by default. We use the `--config` option here only to show that you can pass a configuration of any name. This will be useful for more complex configurations that need to be split into multiple files.