kaios: Provide a populated "locales" field in the manifest

The documentation says it's only needed to override values in the main
manifest, but it's apparently required even if you only support one
locale.

kaios/manifest.pl

@@ -46,7 +46,13 @@ print encode_json({
         url => "https://bjh21.me.uk",
     },
     default_locale => "en-GB",
-    locales => [ ],
+    locales => [
+        "en-GB" => {
+            name => $displayname,
+            subtitle => $description,
+            description => $objective,
+        },
+    ],
     categories => ["games"],
     type => "web",
     cursor => JSON::PP::false,