fix: udpate readme docs (#109)

README.md

@@ -1,3 +1,27 @@
 # Graasp App: Calculator
 
-<a href="https://gitlocalize.com/repo/9259?utm_source=badge"> <img src="https://gitlocalize.com/repo/9259/whole_project/badge.svg" /> </a>
+[![translation badge](https://gitlocalize.com/repo/9259/whole_project/badge.svg)](https://gitlocalize.com/repo/9259?utm_source=badge)
+
+## Running the app
+
+You will need an environment file called `.env.development`
+
+```sh
+VITE_PORT=3012
+VITE_GRAASP_APP_KEY=<your key>
+VITE_VERSION=latest
+VITE_GRAASP_API_HOST=http://localhost:3000
+VITE_ENABLE_MOCK_API=false
+```
+
+## Testing the app
+
+You will need an environment file called `.env.development`
+
+```sh
+VITE_PORT=3333
+VITE_GRAASP_APP_KEY=<your key>
+VITE_VERSION=latest
+VITE_GRAASP_API_HOST=http://localhost:3000
+VITE_ENABLE_MOCK_API=true
+```