docs(llamaindex): port cookbook recipes; pin scrapegraph-py ≥ 2.0.1

LlamaIndex integration page now includes the same extraction scenarios as the
official scrapegraph-py cookbook notebooks (company info, GitHub trending,
Wired news, Zillow listings, and a research ReActAgent), ported from the v1
smartscraper API to the v2 extract endpoint so they work with current
dashboard keys.

Also:
- Flag that the pre-built `llama-index-tools-scrapegraphai` package still
  targets v1 and that v2 keys need the SDK-direct approach shown here.
- Fix the stale `base_url` default in the config table
  (`https://v2-api.scrapegraphai.com/api`).
- Pin the Python SDK page to `scrapegraph-py >= 2.0.1`, matching the JS SDK
  page's version note.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: VinciGit00