refactor(docker): streamline Dockerfile and add gunicorn workers

- Remove redundant comments for cleaner readability
- Simplify COPY commands using relative paths
- Condense pip installation RUN command to single line
- Add 3 workers to gunicorn for improved concurrent request handling
- Remove accidentally included .dockerignore content from Dockerfile

This improves Dockerfile maintainability and production performance
by configuring multiple gunicorn workers for better throughput.

dockerfile

@@ -1,35 +1,17 @@
 FROM python:3.11-slim
 
-# Set environment variables
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV PYTHONUNBUFFERED=1
 
-# Set work directory
 WORKDIR /app
 
-# Install dependencies
-COPY requirements.txt /app/
-RUN pip install --upgrade pip && \
-    pip install -r requirements.txt
+COPY requirements.txt .
+RUN pip install --upgrade pip && pip install -r requirements.txt
 
-# Copy project
-COPY . /app/
+COPY . .
 
-# Collect static files
 RUN python manage.py collectstatic --noinput
 
-# Expose port
 EXPOSE 8000
 
-# Run gunicorn
-CMD ["gunicorn", "booking_system.wsgi:application", "--bind", "0.0.0.0:8000"]
-```
-
-**Optional: Create `.dockerignore`:**
-```
-*.pyc
-__pycache__
-db.sqlite3
-.env
-.git
-venv/
+CMD ["gunicorn", "booking_system.wsgi:application", "--bind", "0.0.0.0:8000", "--workers", "3"]