refactor(vite config) & doc (main readme) : Start Frontend with just …

…"npm start" (All-Hands-AI#333)

* frontend : added vite --port 3001 | package.json

 "start" script : added "vite --port 3001" to frontend package.json

Just use npm start ; uses port 3001

* Updated installation section for frontend | README.md

With the addition of "start": "vite --port 3001" to the frontend's package.json, simply use "npm start" to initiate the frontend development environment.

* -modify vite config port to 3001
-Revert "frontend : added vite --port 3001 | package.json"

README.md

@@ -42,7 +42,7 @@ Then in a second terminal:
 ```bash
 cd frontend
 npm install
-npm run start -- --port 3001
+npm start
 ```
 
 You'll see OpenDevin running at localhost:3001

frontend/vite.config.ts

@@ -8,6 +8,6 @@ export default defineConfig({
   plugins: [react(), viteTsconfigPaths()],
   server: {
     // this sets a default port to 3000
-    port: 3000,
+    port: 3001,
   },
 });