adding duckcatgo plugin

[giacomo83m]

I've created a plugin to search duckduckgo for websites and scrape its results for detailed answers, I'm trying to add it to the plugins inventory :)
I've tested the plugin locally, I've added a readme, a setting panel and a thumbnail.

[pieroit]

Thanks @giacomo83m and welcome!
A few suggestions:

• for your next plugins, use the template
• the docstring for tools should be more explicative

Great idea the duckcat_website tool!

[giacomo83m]

thanks, I'll improve the docstring as well