website: Add OpenGraph information

Author: TenSeventy7

static/assets/sitedata/opengraph.jpg

@@ -34,6 +34,11 @@
         <meta name="apple-mobile-web-app-title" content="Fresh" />
         <link rel="manifest" href="/assets/sitedata/site.webmanifest" />
 
+        <!-- OpenGraph -->
+        <meta property="og:title" content="The Fresh Project" />
+        <meta property="og:type" content="website" />
+        <meta property="og:url" content="https://freshroms.github.io/" />
+        <meta property="og:image" content="https://freshroms.github.io/assets/sitedata/opengraph.jpg" />
 
         <!-- Google tag (gtag.js) -->
         <script async src="https://www.googletagmanager.com/gtag/js?id=G-6P5X7GV6EY"></script>