Added a property to check if a meta description is present or not.

[sstottelaar]

Currently it's not possible to see if the page hold a meta description or not, since it retrieves the first paragraph if there is nothing present. I've added a parameter that holds information if there was a meta description present or not, depending on the outcome.

[gabceb]

Hi! Thanks for your PR. Wouldnt !!client.description be equivalent to the newly added descriptionPresent prop?

[sstottelaar]

I'm not sure. Currently if there is no description present, it will look for the first paragraph and get the description from there. So there is no way to tell if the tag is present or not, since it will always be filled. I'm not sure what the !! operator does in this case. Still learning JS, so if I'm mistaken please enlighten me!