Add og:title and og:description meta tags (#59)

index.html

@@ -4,13 +4,19 @@
     <meta charset="utf-8" />
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>Rustpad: Collaborative Code Editor</title>
+    <title>Rustpad</title>
     <meta
       name="description"
       content="An efficient and minimal open-source collaborative text editor based on the operational transformation algorithm."
     />
     <meta name="author" content="Eric Zhang" />
 
+    <meta property="og:title" content="Rustpad: Collaborative Code Editor" />
+    <meta
+      property="og:description"
+      content="An efficient and minimal open-source collaborative text editor based on the operational transformation algorithm."
+    />
+
     <link
       href="https://fonts.googleapis.com/css?family=Raleway:400,300,600"
       rel="stylesheet"