Add flagmoji demo

[AJBrownson]

Description

• Adding a new demo application in the /demos folder
• Addressing hacktoberfest issue: 🤩 Create Flag Emoji Converter (Hacktoberfest Demo) #2564
• A demo web app that accepts user inputs and displays the country's flag and also has support for the English, French and German languages

Key Features:

• Users can enter a country name and get the country's flag as an output
• Utilizes Tolgee for translation of all labels in the app
• English, French and German languages
• Responsive and clean UI

Screenshots

Blog

Article link dev.to

Checklist

• [✓] I have read the Contribution Guide
• [✓] If the PR changes or adds functionality, I have updated the relevant documentation
• [✓] Translate all labels in the App with Tolgee
• [✓] Store the project into /demos folder
• [✓] Add a screenshot or video demo to the PR
• [✓] Write a short article describing your demo app on DEV.to or your blog
• [✓] Please show your support and give a ⭐ to the Tolgee repository