ENH: Add method to pull content from urls in events table

[linwoodc3]

I've already tested, and my function works on most urls, even the non-English websites.

The demo of the content scraper function will be in my next blog post. For gdeltPyR, need to add method that can be used separately; would take too long to return content for a full pull so leave at user's discretion.

This code already works: https://gist.github.com/linwoodc3/e12a7fbebfa755e897697165875f8fdb