Define `globalThis`, leave `global` definition as deprecated.

index.html

@@ -12,7 +12,9 @@
 <div id="helper">Loading Helios...</div>
 <div id="includes">
     <script type='text/javascript'>
+        // TODO remove, deprecated
         var global = typeof global === "undefined" ? window : global || window;
+        var globalThis = typeof globalThis === "undefined" ? window : globalThis || window;
         var base = decodeURIComponent(window.location.hash.slice(1)).replace(/\/$/, "");
         var script = document.createElement("script");
         script.src = base + "/config.js";