fix(config): resolve F-18 — add .env.example with documented environment variables

src/.env.example

@@ -0,0 +1,40 @@
+APP_NAME=SIDES
+APP_ENV=local
+APP_KEY=
+APP_DEBUG=true
+APP_URL=http://localhost:8080
+
+LOG_CHANNEL=stack
+LOG_LEVEL=debug
+
+DB_CONNECTION=pgsql
+DB_HOST=postgres
+DB_PORT=5432
+DB_DATABASE=sides
+DB_USERNAME=sides_user
+DB_PASSWORD=
+
+SESSION_DRIVER=database
+SESSION_LIFETIME=120
+SESSION_ENCRYPT=false
+
+CACHE_STORE=database
+
+QUEUE_CONNECTION=database
+
+MAIL_MAILER=log
+MAIL_FROM_ADDRESS="hello@example.com"
+MAIL_FROM_NAME="${APP_NAME}"
+
+FIREBASE_PROJECT_ID=
+FIREBASE_CREDENTIALS=
+
+FCM_TOPIC_RAINFALL_WARNING=
+FCM_TOPIC_RAINFALL_DANGER=
+
+POSTGRES_DB=sides
+POSTGRES_USER=sides_user
+POSTGRES_PASSWORD=
+
+PGADMIN_EMAIL=admin@example.com
+PGADMIN_PASSWORD=