Frontend: Add content-type meta tag (#977)

frontend/base.html

@@ -5,6 +5,7 @@
     <title ng-bind="pageTitle + ' - EvalAI'"></title>
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <meta name="description" content="EvalAI: Evaluating state of the art in AI">
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 
     <!--Open Graph Related Stuff-->
     <meta property="og:title" content="EvalAI"/>
@@ -16,10 +17,10 @@
 
     <!--Twitter Card Stuff-->
     <meta name="twitter:card" content="summary_large_image"/>
-    <meta name="twitter:title" content="EvalAI"/>
+    <meta name="twitter:title" content="EvalAI: Evaluating state of the art in AI"/>
     <meta name="twitter:image" content="dist/images/challenge_preview.png"/>
     <meta name="twitter:url" content="http://evalai.cloudcv.org"/>
-    <meta name="twitter:description" content="Evaluating state of the art in AI"/>
+    <meta name="twitter:description" content="EvalAI is an open-source web platform for organizing and participating in challenges to push the state of the art on AI tasks."/>
 
     <link rel="shortcut icon" href="dist/images/favicon.ico" type="image/x-icon">
     <link rel="icon" href="dist/images/favicon.ico" type="image/x-icon">