Rename Server keys page to Keys

src/routes/server-keys/+page.svelte

@@ -51,8 +51,8 @@
     }
 </script>
 
-<svelte:head><title>Server keys · Electric Cherry</title></svelte:head>
-<h1>Server keys</h1>
+<svelte:head><title>Keys · Electric Cherry</title></svelte:head>
+<h1>Keys</h1>
 <p>Save a Plutonium key for each server ID, even when the server is not deployed. Destroying a server keeps its saved key.</p>
 <form onsubmit={save}>
     <h2>{editing ? 'Update key' : 'Add key'}</h2>