include component title in OpenGraph description metadata

Author: mojavelinux

src/partials/head-info.hbs

@@ -19,7 +19,7 @@
     {{#if page.component}}
     <meta property="og:site_name" content="Asciidoctor Docs">
     <meta name="twitter:card" content="summary_large_image">
-    <meta property="og:title" content="{{{detag page.title}}}">
+    <meta property="og:title" content="{{{page.component.title}}} - {{{detag page.title}}}">
     <meta property="og:image" content="{{{or site.url siteRootPath}}}/_/img/asciidoctor-og.png">
     <meta name="twitter:site" content="@asciidoctor">
     {{/if}}