fix(docs): update frontend configuration steps in contributing (#895)

Co-authored-by: Ludovic DEHON <tchiot.ludo@gmail.com>

.github/CONTRIBUTING.md

@@ -73,20 +73,24 @@ python3 -m pip install virtualenv
 The frontend is made with [Vue.js](https://vuejs.org/) and located on the `/ui` folder.
 
 - `npm install`
-- create a files `ui/.env.development.local` with content `VUE_APP_API_URL=http://localhost:8080` (or your actual server url)
-- `npm run serve` will start the development server with hot reload.
+- create a files `ui/.env.development.local` with content `VITE_APP_API_URL=http://localhost:8080` (or your actual server url)
+- `npm run dev` will start the development server with hot reload.
 - The server start by default on port 8090 and is reachable on `http://localhost:5173`
 - You can run `npm run build` in order to build the front-end that will be delivered from the
-backend (without running the `npm serve`) above.
-
-> If you have CORS restrictions when using the local development npm server, you need to configure
-> the backend to allow the http://localhost:5173 origin
-> ```cors:
->      enabled: true
->      configurations:
->        all:
->          allowedOrigins:
->            - http://localhost:5173```
+backend (without running the `npm run dev`) above.
+
+If you have CORS restrictions when using the local development npm server, you need to configure the backend to allow the http://localhost:5173 origin in `cli/src/main/resources/application-override.yml`
+
+```yaml
+micronaut:
+  server:
+    cors:
+      enabled: true
+      configurations:
+        all:
+          allowedOrigins:
+            - http://localhost:5173
+```
 
 #### Develop plugins
 A complete documentation for developing plugin can be found [here](https://kestra.io/docs/plugin-developer-guide/).