docs: fixed css_selector for example

[hitesh22rana]

Fix CSS selector in README example

Description

This pull request updates the CSS selector in the Advanced Usage example in the README.md file. The change fixes a non-functioning example and ensures that the crawler can successfully extract content from the NBC News business page.

The previous selector "article.tease-card" was not functioning correctly and failed to extract any data from the NBC News business page. The new selector .wide-tease-item__description successfully targets the description text of the news articles, allowing the crawler to extract the intended content.

Changes

• Updated the css_selector parameter in the crawler.arun() method from "article.tease-card" to ".wide-tease-item__description".