input: Write a python function to format an email template with placeholders using data from a JSON file.
  assert format_template("Dear {{ recipient }},\n\n{{ greeting }},\n\n{{ message }}\n\n{{ signature }}", {"recipient": "John", "greeting": "Hello", "message": "How are you?", "signature": "Best regards"}) == "Dear John,\n\nHello,\n\nHow are you?\n\nBest regards"
  assert format_template("Hi {{ name }},\n\n{{ body }}\n\nThanks,\n{{ sender }}", {"name": "Alice", "body": "Just checking in.", "sender": "Bob"}) == "Hi Alice,\n\nJust checking in.\n\nThanks,\nBob"
  assert format_template("Subject: {{ subject }}\n\n{{ content }}\n\nRegards,\n{{ author }}", {"subject": "Meeting Update", "content": "The meeting is rescheduled.", "author": "Jane"}) == "Subject: Meeting Update\n\nThe meeting is rescheduled.\n\nRegards,\nJane"
output: def format_template(template, data):
      for key, value in data.items():
          template = template.replace("{{ " + key + " }}", value)
      return template