add: API server(#422)

Add an example of api server so that devs can quickly get up a bot running along with its api

examples/api_server/Dockerfile

@@ -0,0 +1,11 @@
+FROM python:3.11 AS backend
+
+WORKDIR /usr/src/api
+COPY requirements.txt .
+RUN pip install -r requirements.txt
+
+COPY . .
+
+EXPOSE 5000
+
+CMD ["python", "api_server.py"]