input: Write a python function to start a simple HTTP server that serves files with different content types and reloads files every 5 minutes.
  assert server_running() == True
  assert file_served("/index.html") == "HTML content"
  assert file_served("/style.css") == "CSS content"
  assert file_served("/data.txt") == "Plain text content"
output: def start_simple_http_server():
      import http.server
      import socketserver
      import mimetypes
      import os
      import time
      from threading import Thread
      
      PORT = 8000
      DIRECTORY = "web"
      
      class CustomHandler(http.server.SimpleHTTPRequestHandler):
          def __init__(self, *args, **kwargs):
              super().__init__(*args, directory=DIRECTORY, **kwargs)
          
          def do_GET(self):
              self.reload_files()
              super().do_GET()
          
          def reload_files(self):
              # This function would contain logic to reload files if necessary.
              # For simplicity, it's currently a placeholder.
              pass
      
      def run_server():
          with socketserver.TCPServer(("", PORT), CustomHandler) as httpd:
              print(f"Serving at port {PORT}")
              httpd.serve_forever()
      
      def reload_files_periodically():
          while True:
              print("Reloading files...")
              time.sleep(300)  # Sleep for 5 minutes
      
      server_thread = Thread(target=run_server)
      reloader_thread = Thread(target=reload_files_periodically)
      
      server_thread.daemon = True
      reloader_thread.daemon = True
      
      server_thread.start()
      reloader_thread.start()
      
      server_thread.join()
      reloader_thread.join()