Add description method to WikiCookbook scraper

[TheEpic-dev]

Hey. This PR implements the description() method for the wikibooks scraper. I updated the unit tests, and also manually tested different types of recipes, like:

• https://en.wikibooks.org/wiki/Cookbook:Pumpkin_Pie (one <p> tag and a TOC)
• https://en.wikibooks.org/wiki/Cookbook:Afghan_Bread (multiple <p> tags and a TOC)
• https://en.wikibooks.org/wiki/Cookbook:Aubergine_and_Onion_Vegetable_Pie (one <p> tag and no TOC)

[bfcarpio]

I had to double check the docs just to make sure.It looks odd to use find() in a loop construct when it would appear to only return one item.

[bfcarpio]

Looks good! 🍺 Thank you very much!