docs: add DOCKER_GUIDE.md and fix .env parsing; chore: update docker and script configurations

docker/Dockerfile.bot

@@ -0,0 +1,20 @@
+FROM python:3.11-slim
+
+WORKDIR /app
+
+# Copy requirements first
+COPY requirements_bot.txt .
+
+# Install dependencies
+RUN pip install --no-cache-dir -r requirements_bot.txt
+
+# Copy application code
+COPY src/ ./src/
+COPY config/ ./config/
+COPY .env .
+
+# Set Python path
+ENV PYTHONPATH=/app
+
+# Run the bot
+CMD ["python", "src/strategies/ping_pong_bot.py"]