⭐️ Meta: add `property` attribute by @tierracero

The Open Graph protocol enables any web page to become a rich object in a social graph.

This kind of meta tags

<meta property="og:title" content="The Rock" />
<meta property="og:type" content="video.movie" />
<meta property="og:url" content="https://www.imdb.com/title/tt0117500/" />
<meta property="og:image" content="https://ia.media-imdb.com/images/rock.jpg" />

Now could be declared the following way

Meta().property("og:title").content("The Rock")
Meta().property("og:type").content("video.movie")
Meta().property("og:url").content("https://www.imdb.com/title/tt0117500/")
Meta().property("og:image").content("https://ia.media-imdb.com/images/rock.jpg")