Update src/content/docs/workers/testing/vitest-integration/configuration.mdx

Author: Oxyjun

src/content/docs/workers/testing/vitest-integration/configuration.mdx

@@ -49,7 +49,7 @@ Custom Vitest `environment`s or `runner`s are not supported when using the Worke
 
 The following APIs are exported from the `@cloudflare/vitest-pool-workers/config` module.
 
-### defineWorkersConfig(options)
+### `defineWorkersConfig(options)`
 
 Ensures Vitest is configured to use the Workers integration with the correct module resolution settings, and provides type checking for [WorkersPoolOptions](#workerspooloptions). This should be used in place of the [`defineConfig()`](https://vitest.dev/config/file.html) function from Vitest. It also accepts a `Promise` of `options`, or an optionally-`async` function returning `options`.