docs: in vite-dev-server example don't require the config (#15866)

* refactor: simplify vite example

* docs: document the vite server options in TSDoc

Co-authored-by: Lachlan Miller <lachlan.miller.1990@outlook.com>

npm/vite-dev-server/cypress/plugins.js

@@ -1,11 +1,13 @@
-import { startDevServer } from '@cypress/vite-dev-server'
-import viteConfig from '../vite.config'
+const path = require('path')
+const { startDevServer } = require('../dist')
 
 module.exports = (on, config) => {
   on('dev-server:start', async (options) => {
     return startDevServer({
       options,
-      viteConfig,
+      viteConfig: {
+        configFile: path.resolve(__dirname, '..', 'vite.config.ts'),
+      },
     })
   })
 

npm/vite-dev-server/src/startServer.ts

@@ -14,10 +14,17 @@ interface Options {
 }
 
 export interface StartDevServer {
-  /* this is the Cypress options object */
+  /**
+   * the Cypress options object
+   */
   options: Options
-  /* support passing a path to the user's webpack config */
-  viteConfig?: UserConfig // TODO: implement taking in the user's vite configuration. Right now we don't
+  /**
+   * By default, vite will use your vite.config file to
+   * Start the server. If you need additional plugins or
+   * to override some options, you can do so using this.
+   * @optional
+   */
+  viteConfig?: UserConfig
 }
 
 const resolveServerConfig = async ({ viteConfig, options }: StartDevServer): Promise<InlineConfig> => {