feat(misc) Add OpenGraph and Twitter metadata (#2414)

src/server.jsx

@@ -11,6 +11,7 @@ import Site from './components/Site/Site';
 
 // Import Images
 import Favicon from './favicon.ico';
+import Logo from './assets/logo-on-white-bg.svg';
 
 // Define bundles (previously used `Object.values(locals.assets)`) but
 // can't retrieve from there anymore due to separate compilation.
@@ -23,6 +24,7 @@ const bundles = [
 export default locals => {
   let { assets } = locals.webpackStats.compilation;
   let title = getPageTitle(locals.content, locals.path);
+  let description = 'webpack is a module bundler. Its main purpose is to bundle JavaScript files for usage in a browser, yet it is also capable of transforming, bundling, or packaging just about any resource or asset.';
 
   return ReactDOMServer.renderToString(
     <StaticRouter location={locals.path} context={{}}>
@@ -32,7 +34,16 @@ export default locals => {
           <meta name="theme-color" content="#2B3A42" />
           <meta name="viewport" content="width=device-width, initial-scale=1" />
           <title>{title}</title>
-          <meta name="description" content="webpack is a module bundler. Its main purpose is to bundle JavaScript files for usage in a browser, yet it is also capable of transforming, bundling, or packaging just about any resource or asset." />
+          <meta name="description" content={ description } />
+          <meta property="og:site_name" content="webpack" />
+          <meta property="og:type" content="website" />
+          <meta property="og:title" content={ title } />
+          <meta property="og:description" name="description" content={ description } />
+          <meta property="og:image" content={ Logo } />
+          <meta property="twitter:card" content="summary" />
+          <meta property="twitter:site" content="@webpack" />
+          <meta property="twitter:creator" content="@webpack" />
+          <meta property="twitter:domain" content="https://webpack.js.org/" />
           <link rel="icon" type="image/x-icon" href={ Favicon } />
           { Object.keys(assets).filter(asset => /\.css$/.test(asset)).map(path => (
             <link key={ path } rel="stylesheet" href={ `/${path}` } />