Add a few more items to header

Author: Mikolaj

index.html

@@ -8,6 +8,11 @@
     <link rel="mask-icon" href="/safari-pinned-tab.svg" color="#5bbad5">
     <meta name="theme-color" content="#ffffff">
 
+    <meta charset='utf-8' />
+    <meta http-equiv="X-UA-Compatible" content="chrome=1" />
+    <meta name="description" content="LambdaHack : a small dungeon crawler illustrating the roguelike game engine of the same name" />
+    <meta name="keywords" content="roguelike, tactical squad game, procedurally generated, Haskell, free software, gameplay, replayability, turn based" >
+
     <script language="javascript" src="https://github.com/LambdaHack/lambdahack.github.io/releases/download/newestJS/all.js"></script>
 
     <title>LambdaHack</title>