edit wording

README.md

@@ -80,13 +80,17 @@ yarn lint
 In your production app, you must set some env variables [like the .env.example file here](https://gitlab.com/geovisio/website/-/blob/feat/instance-customization/.env.example)
 
 ```sh
+npm install
 npm run build
+npm run start
 ```
 
 or
 
 ```sh
+yarn install
 yarn build
+yarn start
 ```
 
 ## Instance customization