Improve documentation and metadata tagging for Dockerfile

- Add descriptive labels to the Dockerfile
- Enhance code readability and maintainability in the Dockerfile

Author: johnnyhuy

Dockerfile

@@ -8,4 +8,8 @@ COPY . .
 
 RUN pip install --no-cache-dir -r requirements.txt
 
-CMD ["python", "/app/transcribe_me/main.py"]
+CMD ["python", "/app/transcribe_me/main.py"]
+
+LABEL org.opencontainers.image.source=https://github.com/echohello-dev/transcribe-me
+LABEL org.opencontainers.image.description="The transcriber that uses Anthropic and OpenAI."
+LABEL org.opencontainers.image.licenses=MIT