Remove lines that do not start with a letter or a quote.

  From inspecting the data, this seems to leave in most prose and remove
  most weird stuff.

  Args:
    text: a string
  Returns:
    a string

def _remove_boring_lines(text):
  """Remove lines that do not start with a letter or a quote.

  From inspecting the data, this seems to leave in most prose and remove
  most weird stuff.

  Args:
    text: a string
  Returns:
    a string
  """
  lines = text.split("\n")
  filtered = [line for line in lines if re.match("[a-zA-z\"\']", line)]
  return "\n".join(filtered)