fix(Configuration): correct typo in the setupMiddlewares example (webpack#6352)

The injected middleware is the first in the array, it makes more sense to call it like that.

Author: TPXP

src/content/configuration/dev-server.mdx

@@ -1581,7 +1581,7 @@ module.exports = {
       // Use the `unshift` method if you want to run a middleware before all other middlewares
       // or when you are migrating from the `onBeforeSetupMiddleware` option
       middlewares.unshift({
-        name: 'fist-in-array',
+        name: 'first-in-array',
         // `path` is optional
         path: '/foo/path',
         middleware: (req, res) => {