Update frontend module's README.md

frontend/README.md

@@ -1,3 +1,54 @@
-# frontend
+# Down The Aisle (Frontend) 🖥️📱🌐
 
-A new Flutter project.
+This module contains the frontend app code for the `Down The Aisle` system.
+
+## 🎬 Getting Started
+
+This module utilises the following 2 app environments:
+
+1. Development (`dev`)
+2. Production (`prod`)
+
+and it does so with the help of environment variables. The name of the environment variable is `APP_ENV` and it can be added either in the `flutter run` command (for example: `fvm flutter run -t main.dart --dart-define APP_ENV=dev`), otherwise, it can be added in your IDEs configuration settings as well. For example, for VSCode, after cloning the repository, you should see a file named `launch.json` inside the `.vscode` directory that contains the following code:
+
+```json
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "frontend",
+            "cwd": "frontend",
+            "request": "launch",
+            "type": "dart",
+            "toolArgs": ["--dart-define", "APP_ENV=dev"]
+        },
+        {
+            "name": "frontend (profile mode)",
+            "cwd": "frontend",
+            "request": "launch",
+            "type": "dart",
+            "flutterMode": "profile",
+            "toolArgs": ["--dart-define", "APP_ENV=dev"]
+        },
+        {
+            "name": "frontend (release mode)",
+            "cwd": "frontend",
+            "request": "launch",
+            "type": "dart",
+            "flutterMode": "release"
+        }
+    ]
+}
+```
+> For IntelliJ based IDEs, you should be able to set up the same by clicking on `Edit Configurations` and adding the same settings as above
+
+The module also utilises [dotenv](https://pub.dev/packages/dotenv) for secret management and it requires you to manually create 2 files in the `down_the_aisle/frontend/` directory:
+
+1. dotenv.dev
+2. dotenv.prod
+
+and both the files should contain the following key(s) (with their value(s)):
+```env
+BASE_URL=http://localhost:8080
+```
+> The value above is meant for the `dev` environment to work properly when running the `backend` dart-frog module on `localhost`. For the `prod` environment to work, you will need to set up a project on https://globe.dev and deploy the `backend` app on it (its instructions are given in `backend` module's [README.md](../backend/README.md)).