Add label to frontend Dockerfile

Author: M4RC02U1F4A4

frontend/Dockerfile

@@ -6,4 +6,5 @@ COPY package.json /react-app/
 COPY tailwind.config.js /react-app/
 RUN npm install
 RUN npx tailwindcss -i /react-app/public/index.css -o /react-app/public/main.css
+LABEL org.opencontainers.image.source=https://github.com/M4RC02U1F4A4/YouTube-RSS
 CMD ["npm", "start"]