code: def doctree_read(app, doctree):
      
      if app.env.docname == "index":
          all_docs = set()
          insert = True
          nodes = doctree.traverse(toctree)
          toc_entry = "%s/index" % app.config.autoapi_root
          add_entry = (
              nodes
              and app.config.autoapi_generate_api_docs
              and app.config.autoapi_add_toctree_entry
          )
          if not add_entry:
              return
          # Capture all existing toctree entries
          for node in nodes:
              for entry in node["entries"]:
                  all_docs.add(entry[1])
          # Don't insert autoapi it's already present
          for doc in all_docs:
              if doc.find(app.config.autoapi_root) != -1:
                  insert = False
          if insert and app.config.autoapi_add_toctree_entry:
              # Insert AutoAPI index
              nodes[-1]["entries"].append((None, u"%s/index" % app.config.autoapi_root))
              nodes[-1]["includefiles"].append(u"%s/index" % app.config.autoapi_root)
              message_prefix = bold("[AutoAPI] ")
              message = darkgreen(
                  "Adding AutoAPI TOCTree [{0}] to index.rst".format(toc_entry)
              )
              LOGGER.info(message_prefix + message)
docs: Inject AutoAPI into the TOC Tree dynamically.