class_docstr: Search index is a collection of pages and sections (heading
  tags and their following content are sections).
code: def __init__(self, **config) -> None:
      self._entries: list[dict] = []
      self.config = config
  
imports: from __future__ import annotations
  import json
  import logging
  import os
  import re
  import subprocess
  from html.parser import HTMLParser
  from typing import TYPE_CHECKING
label_desc: Use image node_id 1 to create a new SearchIndex object  with example: obj = SearchIndex()