new rule: requireHyphenBeforeDescription

#50

This might need some more tests?

I'm assuming most people want the space so its like ` - description` not ` -description`

so it works like ` if (tag.description.substring(0, 2) !== '- ') {` 


Can you check `location`? Something tells me that `column` should be passed as third parameter and easier to pass here `.loc` property