feat: update .env.example to include Bitly and OpenAI API keys

.env.example

@@ -1,27 +1,32 @@
-APP_NAME=Surveyr
-APP_ENV=local
-APP_KEY=
-APP_DOWN=false
-APP_DEBUG=false
-APP_PORT=8000
-APP_URL=http://localhost:8000/
-
-DB_CONNECTION=mysql
-DB_HOST=127.0.0.1
-DB_PORT=3306
-DB_DATABASE=surveyr
-DB_USERNAME=root
-DB_PASSWORD=
-DB_CHARSET=utf8
-DB_COLLATION=utf8_unicode_ci
-
-MAIL_DRIVER=smtp
-MAIL_HOST=smtp.mailtrap.io
-MAIL_PORT=2525
-MAIL_DEBUG=SERVER
-MAIL_USERNAME=null
-MAIL_PASSWORD=null
-MAIL_ENCRYPTION=null
-
-GOOGLE_CLIENT_ID_KEY=your-google-client-idd
-GOOGLE_CLIENT_SECRET_KEY=your-google-client-secret
+APP_NAME=Surveyr
+APP_ENV=local
+APP_KEY=
+APP_DOWN=false
+APP_DEBUG=false
+APP_PORT=8000
+APP_URL=http://localhost:8000/
+
+DB_CONNECTION=mysql
+DB_HOST=127.0.0.1
+DB_PORT=3306
+DB_DATABASE=surveyr
+DB_USERNAME=root
+DB_PASSWORD=
+DB_CHARSET=utf8
+DB_COLLATION=utf8_unicode_ci
+
+MAIL_DRIVER=smtp
+MAIL_HOST=smtp.mailtrap.io
+MAIL_PORT=2525
+MAIL_DEBUG=SERVER
+MAIL_USERNAME=null
+MAIL_PASSWORD=null
+MAIL_ENCRYPTION=null
+
+GOOGLE_CLIENT_ID_KEY=your-google-client-idd
+GOOGLE_CLIENT_SECRET_KEY=your-google-client-secret
+
+BITLY_API_KEY=bitly-api-key
+
+OPENAI_API_KEY=your-openai-api-key
+OPENAI_TEXTGEN_MODEL=gpt-4o