Add wikipedia service

[vitkhab]

Proposed fix to #13

I used https://github.com/goldsmith/Wikipedia as an example and https://www.mediawiki.org/wiki/Special:ApiSandbox for checking requests to API.

How it works:

• script requests wiki for 3 top search results
• if there are any results script shows its title, url to the page and short description (description is trimmed of html tags and "Play media" string at the beginning)
• if there is no result, script return suggestion
• if there is no suggestion to return then it excuses itself with 'Found nothing :(' string

Known issues:

• Slack won't show preview for the link that already have been posted in channel last hour so I added short description to output
• Search works only in English wikipedia. I need help in making decision how to add multi language support

Example of work:

[vicky002]

This is great @vitkhab ! Thanks for adding Wikipedia Service, a much required service in Fabulous.

For multi-language, I'll see what can be done and get back. I'd recommend you to create an issue for that.

Thank you @vitkhab

Keep Contributing.

~ Vikesh